On the authority of Anas, may Allah be pleased with him, who said: "My paternal uncle Anas bin al Nadir was absent from the battle of Badr, and he said: ‘O Messenger of Allah, I was absent from the first battle in which you fought the polytheists but if Allah provides me with a second opportunity to participate in a battle with the polytheists, then Allah will witness my actions!’ And when the Day of Uhud arrived and the Muslims retreated, he said: ‘O Allah, I ask you to forgive my brothers for their actions and I excuse myself from the actions of the polytheists!’ Then he rushed forward and met Sad bin Muadh and said: ‘O Sad bin Muadh, by Allah I smell its (Jannat's) scent from below Uhud!’ Sad said: ‘O Messenger of Allah, I could not do what he did.’ Anas said: ‘We found him with some eighty wounds either from swords, spears or arrows. We found him murdered and mutilated by the polytheists. No one recognised him except his sister, and even she recognised him by his fingers.’ Anas said: ‘We used to think, or suppose, that this verse came down concerning him and people like him: ‘Among the believers are men who have been true to their covenant with Allah..’ up to the end of the verse (Surat al-Ahzaab, ayah 23).’ [Bukhari)
The covenant with Allah was that we would give our lives and wealth in exchange for eternity in Jannat. No being gets this gift except those humans who recognize their Lord and are true to their bargain. A worthy bargain indeed.