Concise Bible Dictionary:
The name given to the Chaldee version or paraphrase of the Old Testament It was made professedly because the Jews who returned from exile knew that language well. Explanations were added, which crept into the text. There are ten Targums of parts of the Old Testament The principal ones are the Pentateuch by Onkelos, and the books of Joshua, Judges, Samuel, Kings, and the Prophets (except Daniel), by Jonathan Ben Uzziel.
The language agrees with the Chaldaic or Aramaic parts of Daniel and Ezra. It is easy to understand that pious Jews who did not return under Ezra and Nehemiah, and were gradually losing the use of the Hebrew tongue (as well as their descendants born in captivity) would value such a translation; and it has been stated that for centuries the Targums were publicly read on the Sabbaths, festivals, &c., their language being the only one understood by the greater part of the Jews even in Palestine.
As an illustration Gen. 22:10-13 is quoted from the Pentateuch of Onkelos, and from the one known as the Pseudo-Jonathan. This latter is of much later date, as far as dates are known, and has words of other languages here and there.
ONKELOS. “And Abraham stretched forth his hand, and took the knife to immolate his son. And the angel of the Lord called him from the heavens and said, Abraham, Abraham. And he said, Here am I. And he said, Stretch not forth thy hand to the youth, nor do aught to him, for now I know that thou fearest God, and hast not spared thine only son for my sake. And Abraham lifted up his eyes after these [words] and looked, and behold a ram caught in a tree by his horns. And Abraham went and brought the ram, and offered him for a burnt offering instead of his son.”
PSEUDO-JONATHAN. “And Abraham stretched out his hand and took the knife to slay his son. And Isaac answered and said to his father, Bind me properly, lest I should tremble through the affliction of my soul, and be cast into the pit of destruction, for profaneness shall be found in thy offering. The eyes of Abraham were intent upon the eyes of Isaac; and the eyes of Isaac were intent upon the angels on high. Isaac beheld them, but Abraham saw them not. The angels on high answered, Come, behold how these are alone in the world; the one slays the other; he who slays delays not; he that is slain reaches forth his neck. And the angel of the Lord called him from the heavens, and said to him, Abraham, Abraham. And he said, Here am I. Then he said, Stretch not out thy hand to the young man, nor do him any harm, for now it is manifest before me that thou fearest the Lord, and hast not withheld thy son, thy only-begotten from me. Then Abraham lifted up his eyes and looked, and behold a ram, which had been created between the evenings of the foundation of the world, was caught in the entanglement of a tree by his horns. So Abraham went and took him, and offered him for a burnt offering instead of his son.”
It will be seen that while the one is a comparatively correct translation of the Hebrew, the other has useless and undignified additions. A third translation, known as the Jerusalem Targum, has also some of the same additions.