Thy life shall hang in doubt before thee - i. e. shall be hanging as it were on a thread, and that before thine own eyes. The fathers regard this passage as suggesting in a secondary or mystical sense Christ hanging on the cross, as the life of the Jews who would not believe in Him.

And thy life shall hang in doubt before thee,.... Whether it shall be spared or not by the enemy:
and thou shalt fear day and night; being in continual dread of being killed:
and shalt have none assurance of thy life; of its being continued a moment scarcely, but live in constant fear and expectation of its being taken away.

"Thy life will be hung up before thee," i.e., will be like some valued object, hanging by a thin thread before thine eyes, which any moment might tear down (Knobel), that is to say, will be ever hanging in the greatest danger. "Thou wilt not believe in thy life," i.e., thou wilt despair of its preservation (cf. Job. Deuteronomy 24:22).
(Note: "I have never seen a passage which describes more clearly the misery of a guilty conscience, in words and thoughts so fitting and appropriate. For this is just the way in which a man is affected, who knows that God is offended, i.e., who is harassed with the consciousness of sin"' (Luther).)

Thy life shall hang in doubt - Either because thou art in the hands of thy enemies that have power, and want no will, to destroy thee: or because of the terrors of thy own mind, and the guilt of thy conscience making thee to fear, even where no fear is.