As a servant (or, a slave) panteth for the shadow; i.e. longs for the shades of evening to descend and bring the day to a close. The slavery of Job's time was probably not unlike that of captive races in Egypt, so graphically portrayed in the early chapters of Exodus.
The captive, working from morning to night at exhausting labour, would long intensely for the night to arrive, when his toil would come to an end. The inference is not drawn, but clearly is—so Job may be excused if he longs for death, now that he has reached old age, and that the work of his life is manifestly ended.
And as an hireling looketh for the reward of his work; rather, for his wages. The word used ( פעל) has the two meanings of "work" and "the wages of work" (see Jeremiah 22:13).