ثُمَّ أَمَاتَهُ فَأَقْبَرَهُ (Later, he made him die, and put him into the grave..80:21) After mentioning the inception of human life, Allah points to its end, that is, death and grave. Death has been mentioned here in the context of blessings of Allah. It indicates that death is a blessing rather than a calamity. The Holy Prophet ﷺ is reported to have put it thus: تحفَۃ المؤمِن الموت "The gift of a believer is death." Moreover, there is a profound wisdom in death at macro level for the entire world.
The phrase فَأَقْبَرَهُ fa-aqbarah (and put him into the grave) describes another blessing of Allah, in that when man is dead, he is not left lying on the earth like other animals where he might rot, blow up and burst [ and probably be ravaged by vultures or beasts ]. But, even after death, he is honoured in the most befitting manner. His body is washed ceremonially, enshrouded in clean cloths, and buried in a grave with respect.
This verse also indicates that it is obligatory to bury a dead human body.