Sunan an-Nasa'i, Hadith 1634 ⓘ
It was narrated that Anas bin Malik said: "The Messenger of Allah said: 'On the night on which I was taken on the Night Journey, I passed by Musa, peace be upon him, and he was praying in his grave.'"
أَخْبَرَنَا عَلِيُّ بْنُ خَشْرَمٍ، قَالَ حَدَّثَنَا عِيسَى، عَنْ سُلَيْمَانَ التَّيْمِيِّ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَرَرْتُ لَيْلَةَ أُسْرِيَ بِي عَلَى مُوسَى عَلَيْهِ السَّلاَمُ وَهُوَ يُصَلِّي فِي قَبْرِهِ " .
also referenced under: Book 20, Hadith 37 (In-Book) & Volume 2, Book 20, Hadith 1635 (DarusSalam)