But it's in the plural…

The use of a morphologically plural term for a singular referent that is a deity is an ANE literary convention, where it is used to flatter an Amarna-era pharaoh or refer to a Phoenician deity. Interpreters have considered this manner of marking a singular referent as an honorific expression, a plural of majesty, an expression of a superlative nature, or most plausibly in the case of the OT, as an abstraction indicating the essence of deity. However we sort out the motives of the biblical tradents in their uses of the term, we note that the frequency of its employment in the OT is a distinguishing characteristic of the collection in its ANE setting and a mark of differentiation in the use of generic vocabulary for deity.—J. Andrew Dearman in Divine Doppelgängers: YHWH’s Ancient Look-Alikes, p. 79