WHO SAYS SO?
A previous church I served had a lot of acreage and had turned part of it into 3 softball diamonds. Monday - Thursday nights, all summer long, various church leagues played their slow-pitch games there. Three of the leagues ran everything for their evening but one league was run directly by our congregation. For a while I was in charge of the recreation ministry and therefore of that league.
One evening I dropped by to see how the games were going. I got there just in time to see, on one of the diamonds, a young man (late teens or early twenties) decide to show off and act like a jerk. The umpire had called a third strike on him and he proceeded to argue vociferously. When the ump remained silent, this young man gave him a chest bump and then began to holler while nose-to-nose with the umpire. I walked onto the field and told him that his behavior was unacceptable and he was therefore done for the night. Stunned, but not deterred, he looked straight at me and said, "Who says so?"
"I do," I replied.
"And who are you?" he said.
"I'm one of the pastors at this church and I'm in charge of what happens on these fields. You're behavior is way out of line and not acceptable. End of discussion. You have 2 minutes to get 100 yards away from the field or your team forfeits." He began to argue with me -- I simply said "You now have 1 minute and 45 seconds left before I declare a forfeit." At that he, though not happy, left.
As much as I didn't like that confrontation or the young man's attitude, I have to admit he asked a fair question: "Who says so?" In other words, "By whose authority?" God anticipated that the Israelites might ask the very same question when Moses presented the law to them. So before writing out the commandments on the tablets God identified himself -- he established His authority.