John Lightfoot on Matthew 23:16

[Whosoever shall swear by the gold of the Temple, he is a debtor.] These words agree in the same sense with those of the Corban, chapter 15:5. We must not understand the gold of the Temple here, of that gold which shined all about in the walls and ceilings; but the gold here meant is that which was offered up in the Corban. It was a common thing with them, and esteemed as nothing, to swear by the Temple, and by the altar, which we have observed at the 31st verse of the fifth chapter: and therefore they thought themselves not much obliged by it; but if they swore Corban, they supposed they were bound by an indispensable tie. For example: if any one should swear thus, 'By the Temple, or, By the altar, my money, my cattle, my goods shall not profit you'; it was lawful, nevertheless, for the swearer, if he pleased, to suffer them to be profited by these: but if he should swear thus, 'Corban, my gold is for the Temple, Corban, my cattle are for the altar,' this could noways be dispensed with.