Albert Barnes Commentary Psalms 39:4

"Jehovah, make me to know mine end, And the measure of my days, what it is; Let me know how frail I am." — Psalms 39:4 (ASV)

Lord, make me to know my end - This clearly expresses the substance of those anxious and troubled thoughts (Psalms 39:1–2) which he had been unwilling to voice. His thoughts turned to the shortness of life, the mystery of the divine arrangement that made it so short, and the fact that so many troubles and sorrows had been crowded into a life so frail and so soon to end.

With some impatience, and aware that he had been indulging feelings on this subject that were not proper and would cause harm if expressed publicly, he now pours out these feelings before God. He asks what is to be the end of this, how long it is to continue, and when his own sorrows will cease. It was an impatient desire to know when the end would be, coupled with a spirit of unwillingness to submit to the arrangements of Providence that had made his life so brief and appointed so much suffering.

And the measure of my days, what it is - How long I am to live; how long I am to bear these accumulated sorrows.

That I may know how frail I am - Margin: “What time I have here.” Professor Alexander renders this: “when I shall cease.” So DeWette. The Hebrew word used here—חדל châdêl—means “ceasing to be;” hence, “frail;” then, destitute, left, forsaken. An exact translation would be, “that I may know at what (time) or (point) I am ceasing, or about to cease.” It is equivalent to a prayer that he might know when these sufferings—when a life so full of sorrow—would come to an end. The language is an expression of impatience, an expression of a feeling that the psalmist knew was not right in itself and would cause harm if expressed publicly. However, the intensity of his feelings would not permit him to restrain it, and therefore, he expresses it before God.

Similar expressions of impatience regarding the sufferings of such a short life, with so little to alleviate its sorrows, can be seen greatly amplified in Job 3:1-26, Job 6:4–12, Job 7:7, and Job 14:1-13. Before we blame the sacred writers for indulging in these feelings, let us carefully examine our own hearts and recall what has passed through our own minds when considering the mysteries of the divine administration. Let us remember that one primary purpose of the Bible is to record the actual feelings of people—not to vindicate them, but to show what human nature is, even in the best circumstances, and what the human heart is when it is still only partially sanctified.