The Targums of Onkelos and Jonathan Ben Uzziel on the Pentateuch - With the Fragments of the Jerusalem Targum; From the Chaldee #221218

Yet to Him who is of necessity One, is here give, and by His own dictate, a plural appellation. This phenomenon, which occurs in a multitude of places in the Old Testament, is explained as being a mere adaptation to the usual style of royalty; - pluralis majestatis, vel excellentiœ. According to this view it does not indicate a plurality of Persons in the Deity, but the multiform and all-comprising perfection of the One God; the index of physical and moral majesty in their highest expression. When, therefore, we read such words as, "Elohim said, Let us make man in Our Image;" (Gen. i. 26;) or, "Behold, the man is become as one of Us;" (Gen iii. 22;) the formula is to e understood after the manner in which we read the plural in a proclamation of one of the kings of the earth. But the insufficiency of this explanation is apparent in the fact, that Elohim is used not only with plural pronouns in the first person, as in thetexts qouted, but with plural adjectives, (Elohim kerobim, "near Gods," Dent. iv. 7; chayim, "living Gods," Jer. x. 10; kedoshim, "holy Gods," Joshua xxvi. 19,) and in concord with plural verbs in the third person. (Gen. xx. 13: hithu Elohim othi; "The Gods caused me to wander."