John Wesley on Numbers 14:18

Visiting the iniquity - These words may seem to be improperly mentioned, as being a powerful argument to move God to destroy this wicked people, and not to pardon them. It may be answered, that Moses useth these words together with the rest, because he would not sever what God had put together. But the truer answer seems to be, that these words are to be translated otherwise, And in destroying he will not utterly destroy, though he visit the iniquity of the fathers upon the children, unto the third and fourth generation.