Al-Matalib al-'Aliyah 3574 — Surah al-Nisa

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that he said: "Fighting (martyrdom) in the way of Allah Almighty becomes an expiation for all sins except the trust. The one martyred in the way of Allah, the Mighty and Majestic, will be brought (on the Day of Resurrection) and it will be said to him: Fulfil your trust. He will say: O my Lord! How can I fulfil it when the world has come to an end? Then it will be said: Take him to al-Hawiyah (Hell). Then, when he has been taken to the deepest depth of al-Hawiyah, that trust of his will be presented before him in exactly the same state as it was on the day it was lost (in the world). He will lift it, load it on his shoulder and climb upward in the Fire, until, when he thinks he is just about to get out of the Fire, that trust will fall down again, and that person too will keep falling down after it for ever and ever." Then Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) recited this blessed verse: "Indeed, Allah commands you to render trusts to their rightful owners" [Surah al-Nisa: 58].
The chain of this report is jayyid (good), and Imam al-Bayhaqi recorded it in Shu'ab al-Iman and Imam al-Tabarani in al-Mu'jam al-Kabir.