ENOfficial
He said that the Prophet’s grave was sprinkled and that the one who sprinkled the water over his grave from a water-skin was Bilal b. Rabah. He began where the head was and sprinkled it to his feet. Baihaqi transmitted it in Dalail an-nubuwa.
Source: sunnah.com
Other translations
Arabic
وَعَن جَابر قَالَ: رُشَّ قَبْرُ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَكَانَ الَّذِي رَشَّ الْمَاءَ عَلَى قَبْرِهِ بِلَالُ بْنُ رَبَاحٍ بِقِرْبَةٍ بَدَأَ مِنْ قِبَلِ رَأْسِهِ حَتَّى انْتَهَى إِلَى رِجْلَيْهِ. رَوَاهُ الْبَيْهَقِيُّ. فِي دَلَائِل النُّبُوَّة
sunnah.com