Woe unto you, ye blind guides, which say, Whosoever shall swear by the temple, it is nothing; but whosoever shall swear by the gold of the temple, he is a debtor! Whosoever shall swear by the gold - The covetous man, says one, still gives preference to the object of his lust; gold has still the first place in his heart. A man is to be suspected when he recommends those good works most from which he receives most advantage.
Is bound thereby, i.e. to fulfill his oath.