Musnad Ahmad 2:234

Bakr ibn Isa narrated to us, Abu Awanah narrated to us, from al-Mughirah, from al-Sha’bi, from Adi ibn Hatim, who said: I came to Umar ibn al-Khattab among a group of my people. He began to assign two thousand [dirhams] to each man from [the tribe of] Tayy, and he turned away from me. I approached him, and he turned away from me. Then I came to him from the direction of his face, and he turned away from me. I said: "O Commander of the Faithful, do you recognize me?" He laughed until he leaned back on his nape, then he said: "Yes, by Allah, I do recognize you. You believed when they disbelieved, and you came forward when they turned away, and you were faithful when they were treacherous. Indeed, the first charity that brightened the face of the Messenger of Allah, peace and blessings of Allah be upon him, and the faces of his companions, was the charity of Tayy; you brought it to the Messenger of Allah, peace and blessings of Allah be upon him." Then he began to apologize, and he said: "I only assigned [these funds] to people whom poverty has afflicted, and they are the masters of their clans, because of the obligations that befall them."