Sahih Muslim 575
Sahih Muslim · Book 5: The Book of Mosques and Places of Prayer · The prostration of recitation
Ibn 'Umar reported:
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا مُحَمَّدُ بْنُ بِشْرٍ ، حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ عُمَرَ ، عَنْ نَافِعٍ ، عَنِ ابْنِ عُمَرَ ، قَالَ رُبَّمَا قَرَأَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْقُرْآنَ فَيَمُرُّ بِالسَّجْدَةِ فَيَسْجُدُ بِنَا حَتَّى ازْدَحَمْنَا عِنْدَهُ حَتَّى مَا يَجِدُ أَحَدُنَا مَكَانًا لِيَسْجُدَ فِيهِ فِي غَيْرِ صَلاَةٍ .
Sometimes the Messenger of Allah (ﷺ) recited the Qur'an, and would pass by (recite) the verse of sajda and performed prostration and he did this along with us, but we were so crowded in his company that none of us could find a place for performing prostration. (and it was done on occasions) other than prayer.