'Hireling' in the Bible

Is there not an appointed time to man upon earth? are not his days also like the days of an hireling?

As a servant earnestly desireth the shadow, and as an hireling looketh for the reward of his work:

Turn from him, that he may rest, till he shall accomplish, as an hireling, his day.

But now the LORD hath spoken, saying, Within three years, as the years of an hireling, and the glory of Moab shall be contemned, with all that great multitude; and the remnant shall be very small and feeble.

For thus hath the Lord said unto me, Within a year, according to the years of an hireling, and all the glory of Kedar shall fail:

And I will come near to you to judgment; and I will be a swift witness against the sorcerers, and against the adulterers, and against false swearers, and against those that oppress the hireling in his wages, the widow, and the fatherless, and that turn aside the stranger from his right, and fear not me, saith the LORD of hosts.

But he that is an hireling, and not the shepherd, whose own the sheep are not, seeth the wolf coming, and leaveth the sheep, and fleeth: and the wolf catcheth them, and scattereth the sheep.

The hireling fleeth, because he is an hireling, and careth not for the sheep.