John Calvin on the Deity of Jesus in the Old Testament (Part 1 of 2)

"But if this does not satisfy the Jews, I know not what [irritating and trivial objections] will enable them to evade the numerous passages in which Jehovah is said to have appeared in the form of an angel (Judg 6,7,13,16-23, etc.).  This angel claims for himself the name of the eternal God.  Should it be alleged that this is done in respect of the office which he bears, the difficulty is by no means solved.  No servant would rob God of his honor, by allowing sacrifice to be offered to himself.  But the angel, by refusing to eat bread, orders the sacrifice due to Jehovah to be offered to him.  Thus the fact itself proves that he was truly Jehovah.  Accordingly, Manoah and his wife infer from the sign, that they had seen not an angel, but God.  Hence Manoah's exclamation, 'We shall die; for we have seen the Lord.'  When the woman replies, 'If Jehovah had wished to slay us, he would not have received the sacrifice at our hand,' she acknowledges that he who is previously called an angel was certainly God.  We may add, that the angel's own reply removes all doubt, 'Why do ye ask my name, which is wonderful?'  Hence the [the lack of reverence to God] of Servetus was the more detestable, when he maintained that God was never manifested to Abraham and the patriarchs, but that an angel was worshiped in his stead.  The orthodox doctors of the church have correctly and wisely expounded, the the Word of God was the supreme angel, who then began, as it were by anticipation, to perform the office of Mediator.  For though he were not clothed with flesh, yet he descended as in an intermediate form, that he might have more familiar access to the faithful.  This closer intercourse procured for him the name of the angel; still, however, he retained the character which justly belonged to him, that of the God of ineffable glory" (John Calvin, Institutes of the Christian Religion).