Sunan Abi Dawud 22530
In-book no 2026حَدَّثَنَا عُثْمَانُ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو أُسَامَةَ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ صلى الله عليه وسلم بِمَعْنَى حَدِيثِ الْقَعْنَبِيِّ . قَالَ وَنَسِيتُ أَنْ أَسْأَلَهُ كَمْ صَلَّى .
This tradition has also been transmitted by Ibn ‘Umar through a different chain of narrators like the one narrated by Al Qa’nabi . This version has “ I forgot to ask the number of rak’ahs he offered.