[Machine] The Messenger of Allah ﷺ said, "There is no prayer without ablution, and there is no ablution for one who does not mention the name of Allah on it. And one who does not believe in Allah does not believe in me, and one who does not believe in me does not recognize the rights of the Ansar."  

قَالَ رَسُولُ اللهِ ﷺ «لَا صَلَاةَ إِلَّا بِوُضُوءٍ وَلَا وُضُوءَ لِمَنْ لَمْ يَذْكُرِ اسْمَ اللهِ عَلَيْهِ وَلَا يُؤْمِنُ بِاللهِ مَنْ لَمْ يُؤْمِنْ بِي وَلَمْ يُؤْمِنْ بِي مَنْ لَمْ يَعْرِفْ حَقَّ الْأَنْصَارِ»  

[Machine] We used to sit with Abi Zuhair Al-Namiri, who was one of the Companions of the Prophet ﷺ . He would speak and tell stories well. When someone among us would make a supplication, he would end it with "Ameen". For in supplication, "Ameen" is like a seal on a document. Abu Zuhair said, "I will tell you about this." One night, we went out with the Messenger of Allah ﷺ and walked until we came across a man in a tent who was extremely earnest in his request. The Messenger of Allah ﷺ stood there and listened to him. Then the Messenger of Allah ﷺ said, "It is obligatory (for the supplication to be answered) if he ends it (with 'Ameen')." A man from the people asked the Messenger of Allah ﷺ , "What is it that makes it obligatory, O Messenger of Allah?" He replied, "If he ends it with 'Ameen', then it is obligatory." The man who asked the Messenger of Allah ﷺ turned away and said, "End it, O so and so, with 'Ameen' and take glad tidings."  

كُنَّا نَجْلِسُ إِلَى أَبِي زُهَيْرٍ النُّمَيْرِيِّ وَكَانَ مِنْ أَصْحَابِ النَّبِيِّ ﷺ فَيَتَحَدَّثُ فَيُحْسِنُ الْحَدِيثَ فَإِذَا دَعَا الرَّجُلُ مِنَّا بِدُعَاءٍ قَالَ اخْتِمُوهُ بِآمِينَ فَإِنَّ آمِينَ فِي الدُّعَاءِ مِثْلُ الطَّابَعِ عَلَى الصَّحِيفَةِ قَالَ أَبُو زُهَيْرٍ وَأُخْبِرُكُمْ عَنْ ذَلِكَ خَرَجْنَا مَعَ رَسُولِ اللهِ ﷺ ذَاتَ لَيْلَةٍ نَمْشِي فَأَتَيْنَا عَلَى رَجُلٍ فِي خَيْمَةٍ قَدْ أَلْحَفَ فِي الْمَسْأَلَةِ فَوَقَفَ رَسُولُ اللهِ ﷺ يَسْتَمِعُ مِنْهُ فَقَالَ رَسُولُ اللهِ ﷺ «أَوْجَبَ إِنْ خَتَمَ» فَقَالَ لَهُ رَجُلٌ مِنَ الْقَوْمِ بِأَيِّ شَيْءٍ يَخْتِمُ يَا رَسُولَ اللهِ؟ قَالَ «بِآمِينَ إِنْ خَتَمَ بِآمِينَ فَقَدْ أَوْجَبَ» فَانْصَرَفَ الرَّجُلُ الَّذِي سَأَلَ رَسُولَ اللهِ ﷺ فَقَالَ «اخْتِمْ يَا فُلَانُ بِآمِينَ وَأَبْشِرْ»