Isaiah 8:3

And I went unto the prophetess ,.... His wife, so called; not because she prophesied, but because she was the wife of a prophet; and besides, the birth of her son later mentioned, and his name, had in them the nature of a prophecy. The phrase of going unto her is an euphemism, a modest way of expressing the conjugal debt:

and she conceived and bare a son ; which Jarchi would have the same with Immanuel in Isaiah 7:14 but this is a later prophecy, and a distinct one from that; and not only the names of the children are different, but the mothers also; the one a virgin, the other the prophet's wife.

Then said the Lord to me, call his name Mahershalalhashbaz : of the signification of this name; see Gill on Isaiah 8:1 . Kimchi thinks that his name did not consist of these four words, only of two of them; and that he was sometimes called "Mahershalal", and sometimes "Hashbaz": both signifying the same thing. Some think that all this was done only in a vision, and not in reality, to declare and confirm what follows; though by that it seems rather to be a real fact.