Musnad Ahmad 847:1

Isma'il narrated to us, Ayyub informed us, from Harun ibn Ri'ab, from Kinanah ibn Nu'aym, from Qabisah ibn al-Mukhariq, who said: I undertook a debt (to reconcile between people), so I came to the Prophet, peace and blessings of Allah be upon him, and asked him about it. He said: "Stay until the charity comes to us, so that we may either pay it from it, or assist you with it." He then said: "Asking is not permissible except for three: A man who undertakes a debt for a people, so he asks for it until he pays it, then he refrains. A man who is struck by a calamity that destroys his wealth, so he asks for it until he obtains what sustains his life, or provides for his livelihood, then he refrains. And a man who is struck by poverty, so he asks until he obtains what sustains his life, or provides for his livelihood, then he refrains. Any asking other than that is unlawful (suht); O Qabisah, its possessor consumes it as unlawful (suht)."