Musnad Ahmad 1153:442

Abdullah ibn Yazid narrated to us, he said: Sa’id—meaning Ibn Abi Ayyub—narrated to me, he said: ‘Uqayl narrated to me, from Ibn Shihab, from Abu Salamah, from ‘Aishah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever among my nation takes on a debt, then strives to pay it off, but dies without having paid it, then I am his guardian."