Musnad Ahmad Hadith 22140

It is narrated from Abu Umamah (may Allah be pleased with him) that the Noble Prophet (ﷺ) organized an army (in which I was also present). I came to the service of the Noble Prophet (ﷺ) and said, "O Messenger of Allah! Pray to Allah for martyrdom for me." The Noble Prophet (ﷺ) prayed, "O Allah! Keep him safe and grant him spoils of war." Thus, we returned safe and sound with the spoils of war. (When the army was organized again, I made the same request and the Noble Prophet (ﷺ) made the same prayer.) The third time when the army was organized, I came to the service of the Noble Prophet (ﷺ) and said, "O Messenger of Allah! I have come to you twice before and requested you to pray to Allah for martyrdom for me, but you prayed for safety and spoils of war, and we returned safe and sound with the spoils of war. Therefore, O Messenger of Allah! Now pray for martyrdom for me." But the Noble Prophet (ﷺ) again prayed for safety and spoils of war, and we returned safe and sound with the spoils of war. After that, I came to the service of the Noble Prophet (ﷺ) and said, "Command me to do some deed." The Noble Prophet (ﷺ) said, "Make fasting obligatory upon yourself, for you will meet (Allah) in the state of fasting." And if during the day smoke was seen rising from their house, people would understand that today a guest has come to them. Abu Umamah (may Allah be pleased with him) says that I continued to act upon this for a long time, as long as Allah willed. Then I came to the court of the Messenger (ﷺ) and said, "O Messenger of Allah! You had commanded me to fast. I hope that Allah has granted us its blessings. Now tell me another deed." The Noble Prophet (ﷺ) said, "Be certain that if you prostrate once for Allah, Allah will, by its blessing, raise your rank by one degree and forgive one sin."