Augustine of Hippo

"Lord, make me to know mine end" [Psalm 39:4]. For some things I have passed by already; and I have arrived at a certain point, and that to which I have arrived is better than that from which I have advanced to this; but yet there remains a point, which has to be left behind. For we are not to remain here, where there are trials, offenses, where we have to bear with persons who listen to us and cavil at us. "Make me to know mine end;" the end, from which I am still removed, not the course which is already before me.

Exposition on Psalm 39 ↗

Ambrose of Milan

It is not that he was enquiring about his own death—death is not the end of one who will rise again—but rather his enquiry concerned that end of which the apostle speaks: "Afterwards there will be the end, when he shall have delivered up the kingdom to God and the Father". … Evil will fade to nothingness, and eternal good will take its place.… That, surely, is the true end. It is not the end of one person alone, but the end of all. Why then does David say "my end"? But consider a moment who it is that is speaking. …

Commentaries on the Twelve Davidic Psalms ↗

Thomas Aquinas

Here he turns to God and is set ablaze. "I spoke with my tongue: Lord, make known to me my end, and the number of my days." Here a twofold petition is set forth. The first, at "Make known to me, Lord, my end." End is taken here as Christ. Rom. 10: "Christ is the end of the law." And he says, "Lord, make known to me Christ." The other petition is at "Make known to me the number of my days," that is, I wish to consider what the present life is like, so that I may compare it to that end; because these days are evil, few, and imperfect, …

Exposition on the Psalms of David ↗