سنن النسائي

It was narrated from 'Abdullah bin Qatadah that he heard Abu Qatadah narrate from the Messenger of Allah (ﷺ), that he stood up among them and said that Jihad in the cause of Allah and belief in Allah are the best of deeds. Then a man stood up and said: "O Messenger of Allah, if I am killed in the cause of Allah, will Allah forgive my sins?" The Messenger of Allah (ﷺ) said: "Yes, if you are killed in the cause of Allah, and you are patient and seek reward, and you are facing the enemy, not running way - except for debt. Jibril (peace be upon him) told me that."