Musnad Abu Ya'la al-Mawsili 243:20

Ubayd Allah ibn Umar ibn Maysarah al-Jushami narrated to us, Yahya ibn Sa’id narrated to us, Qurrah ibn Khalid narrated to us, Humayd ibn Hilal narrated to us, from Abu Burdah, from Abu Musa, who said: I came to the Messenger of Allah (may Allah bless him and grant him peace), along with two men from the Ash’ariyyin. One of them was on my right and the other was on my left. Both of them asked the Messenger of Allah (may Allah bless him and grant him peace) for work, while he was using the siwak (tooth stick). He said: "What do you say, O Abdullah ibn Qays, or O Abu Musa?" I said: "By the One who sent you with the truth, they did not inform me of what was in their hearts, and I did not perceive that they were seeking work." He said: It is as if I am looking at his siwak while it was under his lip, which had retracted. Then he said: "O Abu Musa, we do not—or we will not—appoint to our work one who seeks it. But go you, O Abdullah ibn Qays, or O Abu Musa." So he sent him to Yemen. Then he sent Mu’adh ibn Jabal after him. When he arrived to him, he said to him: "Dismount," and he threw a cushion for him.