Khabab reported,

We migrated with the Prophet ﷺ seeking the pleasure of Allah, so our reward became due upon Allah. Some of us died without having taken any of his reward in this world, among them was Musab bin Umayr. And among us are those whose fruit has ripened, so he is harvesting it.Musab was killed on the day of Uhud, and we could find nothing to shroud him in except a single cloak. When we covered his head with it, his feet were exposed, and when we covered his feet, his head was exposed. So the Prophet ﷺ instructed us to cover his head and place idhkhir grass over his feet.

Bukhari 1276

Sahih

حدثنا عمر بن حفص بن غياث حدثنا أبي حدثنا الأعمش حدثنا شقيق حدثنا

خباب رضي الله عنه قال

هاجرنا مع النبي ﷺ نلتمس وجه الله فوقع أجرنا على الله فمنا من مات لم يأكل من أجره شيئا منهم مصعب بن عمير ومنا من أينعت له ثمرته فهو يهدبها قتل يوم أحد فلم نجد ما نكفنه إلا بردة إذا غطينا بها رأسه خرجت رجلاه وإذا غطينا رجليه خرج رأسه فأمرنا النبي ﷺ أن نغطي رأسه وأن نجعل على رجليه من الإذخر

البخاري 1276صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Funerals
Chapter
If no shroud is found except what covers his head or his feet, cover his head
Numbering
Darussalam 1276
Bukhari 1276