For what pleasure hath he ... - That is, what happiness shall he have in his family? This, it seems to me, is designed to be a reference to their sentiments, or a statement by Job of what “they” maintained. They held, that a man who was wicked, could have none of the comfort which he anticipated in his children, for he would himself be cut off in the midst of life, and taken away.
When the number of his months is cut off in the midst? - When his “life” is cut off - the word “months” here being used in the sense of “life,” or “years.” This they had maintained, that a wicked man would be punished, by being cut off in the midst of his way; compare Job 14:21.