What reward did Mus`ab bin `Umar receive that made Allah's Apostle order to cover his head with a striped cloak and put some Idhkhir over his feet?
 Narrated Khabbab:                     We migrated with Allah's Apostle seeking Allah's Countenance, so our rewards became due and sure with Allah. Some of us passed away without eating anything of their rewards in this world. One of these was Mus`ab bin `Umar who was martyred on the day of the battle of Uhud. We did not find anything to shroud his body with except a striped cloak. When we covered his head with it, his feet remained uncovered, and when we covered his feet with it, his head remained uncovered. So Allah's Apostle ordered us to cover his head with it and put some Idhkhir (i.e. a kind of grass) over his feet. And there are some amongst us whose fruits have ripened and they are collecting them (i.e. they have received their rewards in this world).