Sayyiduna Amir bin Rabi'ah (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) stood at the grave of Sayyiduna Uthman bin Maz'un (may Allah be pleased with him), and by his (peace and blessings be upon him) command water was sprinkled on his grave.
Al-Bazzar recorded it, and its narrators have been declared trustworthy; however, the case of al-Bazzar's teacher Muhammad bin Abdullah is different, as I do not know him.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجنائز / 4249
Hadith Gradingمحدثین:إسناده ضعیف
Hadith Takhrij«اخرجه الامام البزار فى المسند (843) ، أخرجه مسند البزار برقم: 3822»