Sayyiduna Anas (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) went out to relieve himself, and no one followed him except Sayyiduna Umar (may Allah be pleased with him). Sayyiduna Umar (may Allah be pleased with him) had a vessel of water with him. Sayyiduna Umar (may Allah be pleased with him) found the Prophet (peace and blessings be upon him) in prostration, so he moved back a little and stood. When the Prophet (peace and blessings be upon him) raised his blessed head, he said: O Umar! You did well to move back from me. Jibril has just come to me and told me: "Whoever of your Ummah sends blessings upon you once, Allah Almighty will send mercy upon him ten times and will raise him (the narrator says: I think the narration contains these words:) ten degrees."
Al-Bazzar recorded it; its chain contains Salamah bin Wardan, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدعية / 17288