And he said, Hear ye now, O house of David; Is it a small thing for you to weary men, but will ye weary my God also?
Hear ye now, O house of David; (is it) a small thing for you to weary men, but will ye weary my God also? Is it not enough for you? (Numbers 16:9.) The allusion to "David" is in order to contrast his trust, in God with his degenerate descendant Ahaz' distrust.
Weary - try the patience of.
Men - the prophets. Isaiah as yet had given no outward proof that he was from God; but now God has offered a sign, which Ahaz publicly rejects. The sin is therefore now not, merely against "men," but openly against "God." Isaiah's manner therefore changes from mildness to bold reproof.