[Machine] The Messenger of Allah ﷺ used to observe iʿtikāf in the last ten days of Ramadan. Nāfiʿ reported that Abdullah (ibn Umar) showed him the place where the Messenger of Allah ﷺ used to observe iʿtikāf in the mosque.  

أَنَّ رَسُولَ اللهِ ﷺ كَانَ يَعْتَكِفُ فِي الْعَشْرِ الْأَوَاخِرِ مِنْ رَمَضَانَ قَالَ وَقَالَ نَافِعٌ وَقَدْ أَرَانِي عَبْدُ اللهِ الْمَكَانَ الَّذِي كَانَ يَعْتَكِفُ فِيهِ رَسُولُ اللهِ ﷺ فِي الْمَسْجِدِ  

[Machine] The Prophet ﷺ used to lean his head towards me when he was in seclusion, so I would put my feet out for him. He would not enter the house except for a person's need, and Aisha said, "He used to enter upon me while his head was in the mosque, so I would put my feet out for him." It is also narrated from Urwa and Amrah that it is as if he narrated it from Malik, on the narration of Layth and Yunus. As for Malik, he said about it from Urwa and Amrah.  

النَّبِيُّ ﷺ إِذَا اعْتَكَفَ يُدْنِي إِلَيَّ رَأْسَهُ فَأُرَجِّلُهُ وَكَانَ لَا يَدْخُلُ الْبَيْتَ إِلَّا لِحَاجَةِ الْإِنْسَانِ لَفْظُ حَدِيثِ يَحْيَى بْنِ يَحْيَى وَفِي رِوَايَةِ ابْنِ وَهْبٍ عَنِ الْجَمَاعَةِ أَنَّ النَّبِيَّ ﷺ لَمْ يَكُنْ يَدْخُلُ الْبَيْتَ إِلَّا لِحَاجَةِ الْإِنْسَانِ وَقَالَتْ عَائِشَةُ ؓ كَانَ يُدْخِلُ عَلَيَّ رَأْسَهُ وَهُوَ فِي الْمَسْجِدِ فَأُرَجِّلُهُ وَقَالَ عَنْ عُرْوَةَ وَعَمْرَةَ وَكَأَنَّهُ حَمَلَ رِوَايَةَ مَالِكٍ عَلَى رِوَايَةِ اللَّيْثِ وَيُونُسَ وَأَمَّا مَالِكٌ فَإِنَّهُ يَقُولُ فِيهِ عَنْ عُرْوَةَ عَنْ عَمْرَةَ  

[Machine] Narrated Aisha, the wife of Prophet Muhammad, may ﷺ , said that the Prophet used to observe I'tikaf (seclusion for worship) during the last ten days of Ramadan until Allah (God) took him. After him, his wives also observed I'tikaf. The Sunnah (tradition) of I'tikaf is that one should not leave except for necessities and should not return while being sick or have any physical contact with women. And I'tikaf should only be observed in a congregational mosque. The Sunnah for those who observe I'tikaf is to fast.  

عَنْ عَائِشَةَ زَوْجِ النَّبِيِّ ﷺ أَنَّ النَّبِيَّ ﷺ كَانَ يَعْتَكِفُ الْعَشْرَ الْأَوَاخِرَ مِنْ رَمَضَانَ حَتَّى تَوَفَّاهُ اللهُ ﷻ ثُمَّ اعْتَكَفَ أَزْوَاجُهُ مِنْ بَعْدِهِ وَالسُّنَّةُ فِي الْمُعْتَكِفِ أَنْ لَا يَخْرُجَ إِلَّا لِلْحَاجَةِ الَّتِي لَا بُدَّ مِنْهَا وَلَا يَعُودُ مَرِيضًا وَلَا يَمَسُّ امْرَأَةً وَلَا يُبَاشِرُهَا وَلَا اعْتِكَافَ إِلَّا فِي مَسْجِدِ جَمَاعَةٍ وَالسُّنَّةُ فِيمَنِ اعْتَكَفَ أَنْ يَصُومَ  

[Machine] Ibn Abbas and Al-Hasan said, "Do not seclude yourself except in a mosque where prayers are established."  

أَنَّ ابْنَ عَبَّاسٍ وَالْحَسَنَ قَالَا لَا اعْتِكَافَ إِلَّا فِي مَسْجِدٍ تُقَامُ فِيهِ الصَّلَاةُ  

[Machine] Indeed, the most hated things to Allah are innovations (in religion), and among the innovations is seclusion in the mosques that are in the neighborhoods.  

إِنَّ أَبْغَضَ الْأُمُورِ إِلَى اللهِ الْبِدَعُ وَإِنَّ مِنَ الْبِدَعِ الِاعْتِكَافَ فِي الْمَسَاجِدِ الَّتِي فِي الدُّورِ  

[Machine] That the Messenger of Allah ﷺ said: "There is no i'tikaf except in the Masjid al-Haram, or he said except in the three mosques." So Abdullah said, "Perhaps you forgot and they have preserved, or you made a mistake and they doubt me."  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ لَا اعْتِكَافَ إِلَّا فِي الْمَسْجِدِ الْحَرَامِ أَوْ قَالَ إِلَّا فِي الْمَسَاجِدِ الثَّلَاثَةِ فَقَالَ عَبْدُ اللهِ لَعَلَّكَ نَسِيتَ وَحَفِظُوا أَوْ أَخْطَأْتَ وَأَصَابُوا الشَّكُّ مِنِّي