It is narrated from Sayyiduna Jarir bin Abdullah al-Bajali (may Allah be pleased with him) that the Prophet Muhammad (peace be upon him) said: "When the collector of zakat comes to you, he should return from you pleased and satisfied." This is the narration of Thaqafi. And in the narration of San‘ani, it is: "The Messenger of Allah (peace be upon him) commanded us."
Hadith Referenceصحيح ابن خزيمه / جماع أبواب ذكر السعاية على الصدقة / 2341