The Prophet ﷺ said, "Whoever purposely throws himself from a mountain and kills himself, will be in the (Hell) Fire falling down into it and abiding therein perpetually forever; and whoever drinks poison and kills himself with it, he will be carrying his poison in his hand and drinking it in the (Hell) Fire wherein he will abide eternally forever; and whoever kills himself with an iron weapon, will be carrying that weapon in his hand and stabbing his ʿAbdomen with it in the (Hell) Fire wherein he will abide eternally forever."  

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ تَرَدَّى مِنْ جَبَلٍ فَقَتَلَ نَفْسَهُ فَهْوَ فِي نَارِ جَهَنَّمَ يَتَرَدَّى فِيهِ خَالِدًا مُخَلَّدًا فِيهَا أَبَدًا وَمَنْ تَحَسَّى سَمًّا فَقَتَلَ نَفْسَهُ فَسَمُّهُ فِي يَدِهِ يَتَحَسَّاهُ فِي نَارِ جَهَنَّمَ خَالِدًا مُخَلَّدًا فِيهَا أَبَدًا وَمَنْ قَتَلَ نَفْسَهُ بِحَدِيدَةٍ فَحَدِيدَتُهُ فِي يَدِهِ يَجَأُ بِهَا فِي بَطْنِهِ فِي نَارِ جَهَنَّمَ خَالِدًا مُخَلَّدًا فِيهَا أَبَدًا  

who was one of the companions of the tree (who gave the pledge of allegiance to the Prophet ﷺ underneath the tree at Ḥudaybiyyah) that the Messenger of Allah ﷺ said, "Whoever swears by a religion other than Islam then he is really so. A child of Adam is not bound to fulfill a vow to Allah about a thing which he does not possess."

"If someone commits suicide with anything in this world, he will be tortured with it on the Day of Resurrection. If somebody curses a believer then his sin will be as if he killed him. And whoever accuses a believer of kufr (disbelief) then it is as if he killed him."  

وَكَانَ مِنْ أَصْحَابِ الشَّجَرَةِ حَدَّثَهُ أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ: «مَنْ حَلَفَ عَلَى مِلَّةٍ غَيْرِ الإِسْلاَمِ فَهْوَ كَمَا قَالَ؛ وَلَيْسَ عَلَى ابْنِ آدَمَ نَذْرٌ فِيمَا لاَ يَمْلِكُ؛»

«وَمَنْ قَتَلَ نَفْسَهُ بِشَىْءٍ فِي الدُّنْيَا عُذِّبَ بِهِ يَوْمَ الْقِيَامَةِ؛ وَمَنْ لَعَنَ مُؤْمِنًا فَهْوَ كَقَتْلِهِ؛ وَمَنْ قَذَفَ مُؤْمِنًا بِكُفْرٍ فَهْوَ كَقَتْلِهِ۔»  

as follows in Hadith 297. Narrated Abu Huraira: We were in the company of Messenger of Allah ﷺ in a Ghazwa, and he remarked about a man who claimed to be a Muslim, saying, "This (man) is from the people of the (Hell) Fire." When the battle started, the man fought violently till he got wounded. Somebody said, "O Messenger of Allah ﷺ! The man whom you described as being from the people of the (Hell) Fire fought violently today and died." The Prophet ﷺ said, "He will go to the (Hell) Fire." Some people were on the point of doubting (the truth of what the Prophet had said) while they were in this state, suddenly someone said that he was still alive but severely wounded. When night fell, he lost patience and committed suicide. The Prophet ﷺ was informed of that, and he said, "Allah is Greater! I testify that I am Allah's Slave and His Apostle." Then he ordered Bilal to announce amongst the people: 'None will enter Paradise but a Muslim, and Allah may support this religion (i.e. Islam) even with a disobedient man.'  

شَهِدْنَا مَعَ رَسُولِ اللَّهِ ﷺ فَقَالَ لِرَجُلٍ مِمَّنْ يَدَّعِي الإِسْلاَمَ هَذَا مِنْ أَهْلِ النَّارِ فَلَمَّا حَضَرَ الْقِتَالُ قَاتَلَ الرَّجُلُ قِتَالاً شَدِيدًا فَأَصَابَتْهُ جِرَاحَةٌ فَقِيلَ يَا رَسُولَ اللَّهِ الَّذِي قُلْتَ إِنَّهُ مِنْ أَهْلِ النَّارِ فَإِنَّهُ قَدْ قَاتَلَ الْيَوْمَ قِتَالاً شَدِيدًا وَقَدْ مَاتَ فَقَالَ النَّبِيُّ ﷺ إِلَى النَّارِ قَالَ فَكَادَ بَعْضُ النَّاسِ أَنْ يَرْتَابَ فَبَيْنَمَا هُمْ عَلَى ذَلِكَ إِذْ قِيلَ إِنَّهُ لَمْ يَمُتْ وَلَكِنَّ بِهِ جِرَاحًا شَدِيدًا فَلَمَّا كَانَ مِنَ اللَّيْلِ لَمْ يَصْبِرْ عَلَى الْجِرَاحِ فَقَتَلَ نَفْسَهُ فَأُخْبِرَ النَّبِيُّ ﷺ بِذَلِكَ فَقَالَ اللَّهُ أَكْبَرُ أَشْهَدُ أَنِّي عَبْدُ اللَّهِ وَرَسُولُهُ ثُمَّ أَمَرَ بِلاَلاً فَنَادَى بِالنَّاسِ إِنَّهُ لاَ يَدْخُلُ الْجَنَّةَ إِلاَّ نَفْسٌ مُسْلِمَةٌ وَإِنَّ اللَّهَ لَيُؤَيِّدُ هَذَا الدِّينَ بِالرَّجُلِ الْفَاجِرِ  

Messenger of Allah ﷺ and the pagans faced each other and started fighting. When Messenger of Allah ﷺ returned to his camp and when the pagans returned to their camp, somebody talked about a man amongst the companions of Messenger of Allah ﷺ who would follow and kill with his sword any pagan going alone. He said, "Nobody did his job (i.e. fighting) so properly today as that man." Messenger of Allah ﷺ said, "Indeed, he is amongst the people of the (Hell) Fire." A man amongst the people said, "I shall accompany him (to watch what he does)" Thus he accompanied him, and wherever he stood, he would stand with him, and wherever he ran, he would run with him. Then the (brave) man got wounded seriously and he decided to bring about his death quickly. He planted the blade of the sword in the ground directing its sharp end towards his chest between his two breasts. Then he leaned on the sword and killed himself. The other man came to Messenger of Allah ﷺ and said, "I testify that you are Messenger of Allah ﷺ." The Prophet ﷺ asked, "What has happened?" He replied, "(It is about) the man whom you had described as one of the people of the (Hell) Fire. The people were greatly surprised at what you said, and I said, 'I will find out his reality for you.' So, I came out seeking him. He got severely wounded, and hastened to die by slanting the blade of his sword in the ground directing its sharp end towards his chest between his two breasts. Then he eased on his sword and killed himself." when Messenger of Allah ﷺ said, "A man may seem to the people as if he were practising the deeds of the people of Paradise while in fact he is from the people of the Hell) Fire, another may seem to the people as if he were practicing the deeds of the people of Hell (Fire), while in fact he is from the people of Paradise."  

أَنَّ رَسُولَ اللَّهِ ﷺ الْتَقَى هُوَ وَالْمُشْرِكُونَ فَاقْتَتَلُوا فَلَمَّا مَالَ رَسُولُ اللَّهِ ﷺ إِلَى عَسْكَرِهِ وَمَالَ الآخَرُونَ إِلَى عَسْكَرِهِمْ وَفِي أَصْحَابِ رَسُولِ اللَّهِ ﷺ رَجُلٌ لاَ يَدَعُ لَهُمْ شَاذَّةً وَلاَ فَاذَّةً إِلاَّ اتَّبَعَهَا يَضْرِبُهَا بِسَيْفِهِ فَقَالَ مَا أَجْزَأَ مِنَّا الْيَوْمَ أَحَدٌ كَمَا أَجْزَأَ فُلاَنٌ فَقَالَ رَسُولُ اللَّهِ ﷺ أَمَا إِنَّهُ مِنْ أَهْلِ النَّارِ فَقَالَ رَجُلٌ مِنَ الْقَوْمِ أَنَا صَاحِبُهُ قَالَ فَخَرَجَ مَعَهُ كُلَّمَا وَقَفَ وَقَفَ مَعَهُ وَإِذَا أَسْرَعَ أَسْرَعَ مَعَهُ قَالَ فَجُرِحَ الرَّجُلُ جُرْحًا شَدِيدًا فَاسْتَعْجَلَ الْمَوْتَ فَوَضَعَ نَصْلَ سَيْفِهِ بِالأَرْضِ وَذُبَابَهُ بَيْنَ ثَدْيَيْهِ ثُمَّ تَحَامَلَ عَلَى سَيْفِهِ فَقَتَلَ نَفْسَهُ فَخَرَجَ الرَّجُلُ إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَ أَشْهَدُ أَنَّكَ رَسُولُ اللَّهِ قَالَ وَمَا ذَاكَ قَالَ الرَّجُلُ الَّذِي ذَكَرْتَ آنِفًا أَنَّهُ مِنْ أَهْلِ النَّارِ فَأَعْظَمَ النَّاسُ ذَلِكَ فَقُلْتُ أَنَا لَكُمْ بِهِ فَخَرَجْتُ فِي طَلَبِهِ ثُمَّ جُرِحَ جُرْحًا شَدِيدًا فَاسْتَعْجَلَ الْمَوْتَ فَوَضَعَ نَصْلَ سَيْفِهِ فِي الأَرْضِ وَذُبَابَهُ بَيْنَ ثَدْيَيْهِ ثُمَّ تَحَامَلَ عَلَيْهِ فَقَتَلَ نَفْسَهُ فَقَالَ رَسُولُ اللَّهِ ﷺ عِنْدَ ذَلِكَ إِنَّ الرَّجُلَ لَيَعْمَلُ عَمَلَ أَهْلِ الْجَنَّةِ فِيمَا يَبْدُو لِلنَّاسِ وَهْوَ مِنْ أَهْلِ النَّارِ وَإِنَّ الرَّجُلَ لَيَعْمَلُ عَمَلَ أَهْلِ النَّارِ فِيمَا يَبْدُو لِلنَّاسِ وَهْوَ مِنْ أَهْلِ الْجَنَّةِ  

Messenger of Allah ﷺ said, "Amongst the nations before you there was a man who got a wound, and growing impatient (with its pain), he took a knife and cut his hand with it and the blood did not stop till he died. Allah said, 'My Slave hurried to bring death upon himself so I have forbidden him (to enter) Paradise.' "  

قَالَ رَسُولُ اللَّهِ ﷺ كَانَ فِيمَنْ كَانَ قَبْلَكُمْ رَجُلٌ بِهِ جُرْحٌ فَجَزِعَ فَأَخَذَ سِكِّينًا فَحَزَّ بِهَا يَدَهُ فَمَا رَقَأَ الدَّمُ حَتَّى مَاتَ قَالَ اللَّهُ تَعَالَى بَادَرَنِي عَبْدِي بِنَفْسِهِ حَرَّمْتُ عَلَيْهِ الْجَنَّةَ  

Messenger of Allah ﷺ and the pagans faced each other and started fighting. When Messenger of Allah ﷺ returned to his camp and when the pagans returned to their camp, somebody talked about a man amongst the companions of Messenger of Allah ﷺ who would follow and kill with his sword any pagan going alone. He said, "Nobody did his job (i.e. fighting) so properly today as that man." Messenger of Allah ﷺ said, "Indeed, he is amongst the people of the (Hell) Fire." A man amongst the people said, "I shall accompany him (to watch what he does)" Thus he accompanied him, and wherever he stood, he would stand with him, and wherever he ran, he would run with him. Then the (brave) man got wounded seriously and he decided to bring about his death quickly. He planted the blade of the sword in the ground directing its sharp end towards his chest between his two breasts. Then he leaned on the sword and killed himself. The other man came to Messenger of Allah ﷺ and said, "I testify that you are Messenger of Allah ﷺ." The Prophet ﷺ asked, "What has happened?" He replied, "(It is about) the man whom you had described as one of the people of the (Hell) Fire. The people were greatly surprised at what you said, and I said, 'I will find out his reality for you.' So, I came out seeking him. He got severely wounded, and hastened to die by slanting the blade of his sword in the ground directing its sharp end towards his chest between his two breasts. Then he eased on his sword and killed himself." when Messenger of Allah ﷺ said, "A man may seem to the people as if he were practising the deeds of the people of Paradise while in fact he is from the people of the Hell) Fire, another may seem to the people as if he were practicing the deeds of the people of Hell (Fire), while in fact he is from the people of Paradise."  

أَنَّ رَسُولَ اللَّهِ ﷺ الْتَقَى هُوَ وَالْمُشْرِكُونَ فَاقْتَتَلُوا فَلَمَّا مَالَ رَسُولُ اللَّهِ ﷺ إِلَى عَسْكَرِهِ وَمَالَ الآخَرُونَ إِلَى عَسْكَرِهِمْ وَفِي أَصْحَابِ رَسُولِ اللَّهِ ﷺ رَجُلٌ لاَ يَدَعُ لَهُمْ شَاذَّةً وَلاَ فَاذَّةً إِلاَّ اتَّبَعَهَا يَضْرِبُهَا بِسَيْفِهِ فَقَالَ مَا أَجْزَأَ مِنَّا الْيَوْمَ أَحَدٌ كَمَا أَجْزَأَ فُلاَنٌ فَقَالَ رَسُولُ اللَّهِ ﷺ أَمَا إِنَّهُ مِنْ أَهْلِ النَّارِ فَقَالَ رَجُلٌ مِنَ الْقَوْمِ أَنَا صَاحِبُهُ قَالَ فَخَرَجَ مَعَهُ كُلَّمَا وَقَفَ وَقَفَ مَعَهُ وَإِذَا أَسْرَعَ أَسْرَعَ مَعَهُ قَالَ فَجُرِحَ الرَّجُلُ جُرْحًا شَدِيدًا فَاسْتَعْجَلَ الْمَوْتَ فَوَضَعَ نَصْلَ سَيْفِهِ بِالأَرْضِ وَذُبَابَهُ بَيْنَ ثَدْيَيْهِ ثُمَّ تَحَامَلَ عَلَى سَيْفِهِ فَقَتَلَ نَفْسَهُ فَخَرَجَ الرَّجُلُ إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَ أَشْهَدُ أَنَّكَ رَسُولُ اللَّهِ قَالَ وَمَا ذَاكَ قَالَ الرَّجُلُ الَّذِي ذَكَرْتَ آنِفًا أَنَّهُ مِنْ أَهْلِ النَّارِ فَأَعْظَمَ النَّاسُ ذَلِكَ فَقُلْتُ أَنَا لَكُمْ بِهِ فَخَرَجْتُ فِي طَلَبِهِ ثُمَّ جُرِحَ جُرْحًا شَدِيدًا فَاسْتَعْجَلَ الْمَوْتَ فَوَضَعَ نَصْلَ سَيْفِهِ فِي الأَرْضِ وَذُبَابَهُ بَيْنَ ثَدْيَيْهِ ثُمَّ تَحَامَلَ عَلَيْهِ فَقَتَلَ نَفْسَهُ فَقَالَ رَسُولُ اللَّهِ ﷺ عِنْدَ ذَلِكَ إِنَّ الرَّجُلَ لَيَعْمَلُ عَمَلَ أَهْلِ الْجَنَّةِ فِيمَا يَبْدُو لِلنَّاسِ وَهْوَ مِنْ أَهْلِ النَّارِ وَإِنَّ الرَّجُلَ لَيَعْمَلُ عَمَلَ أَهْلِ النَّارِ فِيمَا يَبْدُو لِلنَّاسِ وَهْوَ مِنْ أَهْلِ الْجَنَّةِ