“Woe.” See commentary on Matthew 23:13.
“it is nothing.” The practices regarding oaths reveals the blindness and dishonesty of the religious leaders. Of course they had a “reason” for their view that an oath made by the gold of the sanctuary or the gift on the altar was binding, but an oath made by the sanctuary or altar itself was not binding. It seems that they reasoned that the binding nature of the oath was determined by the value of what the person swore by, and because neither the Temple nor altar was for sale, an oath by those things was not binding (R. L. Harris, Inspiration and Canonicity of the Bible, p. 49, 50). Of course the priests could use this to their advantage, because they could very sincerely swear an oath by the Temple to someone who did not know their customs, knowing full well that they were deceiving the person, and just shrug off their oath if it was not convenient to keep it, saying that “it is nothing,” that is, it is not binding. They were so blind and self-righteous they did not think God would judge such behavior. No wonder Jesus called them “fools,” and “blind,” and said “woe” to them, referring to great distress and disaster.