What is the meaning of the permissibility of wishing for death for one who is confident in his deeds, and is this considered self-admiration of one's deeds?

A Muslim is not permitted to wish for death or pray for it except out of necessity. The situations in which this is permissible are: fearing tribulation concerning one's religion, in the presence of circumstances leading to martyrdom, and for one who is confident in their deeds, out of longing to meet Allah, the Almighty. As for wishing for it merely out of confidence in one's deeds, this is not appropriate, due to what it might lead to in terms of self-admiration and reliance on deeds instead of Allah's mercy.