Musnad Ahmad 108:2

Husayn ibn Ali al-Ju'fi narrated to us, from Za'idah, and Mu'awiyah ibn 'Amr, who said: Za'idah narrated to us, from 'Abd al-Malik ibn 'Umayr, from Rib'i, who said: Abu al-Yusr narrated to me, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever grants respite to one in financial difficulty, or remits [the debt] for him, Allah will shade him in His shade." He [the narrator] said: Mu'awiyah said: "On a day when there is no shade but His shade."