Musannaf Ibn Abi Shayba 13:2210

Abu Bakr narrated to us, he said: Husayn ibn Ali narrated to us, from Za'idah, from Abd al-Malik ibn Umayr, from Rib'i, he said: Abu al-Yusr narrated to me, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever grants respite to one in financial difficulty, or waives [the debt] for him, Allah will shade him in the shade of His Throne."