It was narrated from Anas, from on of the companions of the Prophet ﷺ, that:

The Prophet ﷺ said: 'On the night on which I was taken on the Night Journey, I passed by Musa and he was praying in his grave.'

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنْ سُلَيْمَانَ، عَنْ أَنَسٍ، عَنْ بَعْضِ، أَصْحَابِ النَّبِيِّ ﷺ أَنَّ النَّبِيَّ ﷺ قَالَ " لَيْلَةَ أُسْرِيَ بِي مَرَرْتُ عَلَى مُوسَى وَهُوَ يُصَلِّي فِي قَبْرِهِ " .