Musannaf Ibn Abi Shaybah 10100 — Withholding zakah

It is narrated from Sayyiduna Jarir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "When the zakah collector goes back from you, let him go back in a state of being pleased with you."
Al-Sha'bi said: The one who transgresses in (collecting) zakah is like the one who withholds it.