مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 2104
Fasting
Private Devotional Exercises in a Mosque - Section 2
وَعَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا أَرَادَ أَنْ يَعْتَكِفَ صَلَّى الْفَجْرَ ثُمَّ دَخَلَ فِي مُعْتَكَفِهِ. رَوَاهُ أَبُو دَاوُدَ وَابْنُ مَاجَهْ
‘A'isha said that when God’s messenger intended to engage in private devotion in the mosque he prayed the dawn prayer and then entered his place of seclusion. Abu Dawud and Ibn Majah transmitted it.
Mishkat al-Masabih, 2104