Musannaf Ibn Abi Shayba 37:195

Ghundar narrated to us, from Shu'bah, from 'Amr ibn Murrah, from Abu Wa'il, who said: Abu Musa and Abu Mas'ud entered upon 'Ammar while he was mobilizing the people. Abu Mas'ud said: "We have not seen you do anything since you became a Muslim that we disliked more than your hastening in this matter." 'Ammar said: "And I have not seen either of you do anything since you became Muslims that I disliked more than your lagging behind in this matter." He said: Then he clothed each of them in a garment.