Sahih al-Bukhari, Book 63, Hadith 140 (In-Book) ⓘ

Narrated Khabbab: We migrated with Allah's Messenger 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).

وَحَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنِ الأَعْمَشِ، قَالَ سَمِعْتُ شَقِيقَ بْنَ سَلَمَةَ، قَالَ حَدَّثَنَا خَبَّابٌ، قَالَ هَاجَرْنَا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم نَبْتَغِي وَجْهَ اللَّهِ، وَوَجَبَ أَجْرُنَا عَلَى اللَّهِ، فَمِنَّا مَنْ مَضَى لَمْ يَأْكُلْ مِنْ أَجْرِهِ شَيْئًا، مِنْهُمْ مُصْعَبُ بْنُ عُمَيْرٍ، قُتِلَ يَوْمَ أُحُدٍ فَلَمْ نَجِدْ شَيْئًا نُكَفِّنُهُ فِيهِ، إِلاَّ نَمِرَةً كُنَّا إِذَا غَطَّيْنَا بِهَا رَأْسَهُ خَرَجَتْ رِجْلاَهُ، فَإِذَا غَطَّيْنَا رِجْلَيْهِ خَرَجَ رَأْسُهُ، فَأَمَرَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم أَنْ نُغْطِيَ رَأْسَهُ بِهَا، وَنَجْعَلَ عَلَى رِجْلَيْهِ مِنْ إِذْخِرٍ، وَمِنَّا مَنْ أَيْنَعَتْ لَهُ ثَمَرَتُهُ فَهْوَ يَهْدِبُهَا‏.‏