Sayyidah Umm Maslamah (may Allah be pleased with her) narrates: Abu al-Haytham bin al-Tayyihan al-Ansari came to the Prophet (peace and blessings be upon him) and asked him for a servant. The Prophet (peace and blessings be upon him) promised him that when he received captives, he would give him one. He met Sayyiduna Umar (may Allah be pleased with him), who said: "O Abu al-Haytham! The Prophet (peace and blessings be upon him) has received captives; go to the Prophet (peace and blessings be upon him) and have him fulfil his promise to you." Sayyiduna Abu al-Haytham (may Allah be pleased with him) and Sayyiduna Umar (may Allah be pleased with him) both came to the Prophet (peace and blessings be upon him), and he submitted: "O Messenger of Allah! Abu al-Haytham has come to you so that his promise may be fulfilled." The Prophet (peace and blessings be upon him) said to him: "We have received two black slaves; choose whichever of them you wish." He submitted: "I seek your counsel." The Prophet (peace and blessings be upon him) said: "The one whose counsel is sought is entrusted. Take this one, for he prays among us; and do not beat him, for we have been forbidden from beating those who pray." (Allamah al-Haythami says:) I say: Imam al-Tirmidhi has recorded only this part of the narration: "The one whose counsel is sought is entrusted."
This narration was recorded by Imam Abu Ya'la from his teacher Sufyan bin Waki', who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 13160