But swearing by the altar was a first-century version of crossing your fingers behind your back. The person swearing by the altar believed that oath was not binding and never intended to keep the promise.
Now swearing by the gift on the altar is another thing. Everyone knows that an oath based on the gift on the altar is something you better keep, or else.
The reasoning is contrived. How can an altar or a gift on the altar nullify or validate an oath? But that’s exactly the point. We all know an altar has nothing to do with keeping a promise.
The religious leaders of Jesus’ time liked these integrity loopholes. Jesus cites the case of the man who “dedicates” his wealth and service to God so that he does not have to give them to his aging parents.
But such integrity maneuvers are not new. People have been playing fast and loose with agreements since the dawn of time.
Promises are built on trust. Absent that trust, a promise is just a handful of sand that slips through the fingers. Like my neighbor who emptied the equity of his house to buy adult “toys” and then walked away from his agreement with the bank. Or like the person who signs a contract to do a job for someone and then uses shoddy materials and workmanship.
Jesus said that agreements should need nothing more than a yes or a no. He knew that we humans like to weasel out of our agreements. “Just say yes or no and stick to your agreement,” he implied.
That’s a good way to live.