Musnad Ahmad Hadith 27214

It is narrated from Khabbab (may Allah be pleased with him) that we migrated with the Prophet (ﷺ) solely for the pleasure of Allah, therefore our reward became due upon Allah. Now, some of us have departed from this world and did not partake of any of their reward, among them was Mus'ab bin Umair (may Allah be pleased with him), who was martyred at the time of the Battle of Uhud, and we could not find anything to shroud him with except a single sheet; if we covered his head, his feet would remain uncovered, and if we covered his feet, his head would remain uncovered. The Prophet (ﷺ) instructed us to cover his head and to place a kind of grass called 'izkhir' on his feet. And some among us are those whose fruits have ripened and they are gathering them.