Hadithcore
Bulugh al-Maram, 580

‘Amir bin Rabi’Ah (RAA) narrated that the Messenger of Allah (ﷺ) prayed over ‘Uthman bin Madh’un, then went to the grave and sprinkled three handfuls of soil while he was standing.’ Related by Ad-Darqutni.

وَعَنْ عَامِرِ بْنِ رَبِيعَةَ ‏- رضى الله عنه ‏- { أَنَّ النَّبِيَّ ‏- صلى الله عليه وسلم ‏-صَلَّى عَلَى عُثْمَانَ بْنِ مَظْعُونٍ, وَأَتَى الْقَبْرَ, فَحَثَى عَلَيْهِ ثَلَاثَ حَثَيَاتٍ, وَهُوَ قَائِمٌ } رَوَاهُ اَلدَّارَقُطْنِيّ ُ [1]‏ .‏

References2 variants
In-Book Reference
Book 3, Hadith 49
English Reference
Book 3, Hadith 605