There are many other examples where He tells the people without quoting Scriputres what is really at stake and what they should know (and believe) by that same phrase. He is telling them that which He is thinking, not necessarily that which is written
Oh, now really! I tell you truly, this Whiskey, I mean proven cureall, will do everything from curing the common cold to removing stains from your favorite blue dress... Now, what makes that more or less authoritative than Christ?
Right, you don't know. You can't know because your argument tries to beg off the requirement of authority in trying to sell anything you wish. What utter nonsesnse. Here's a phrase for you "Study to show yourself approved". Jesus established His authority by doing just that - studying scripture to show himself approved - to show that he knew of which he spoke.. that he knew the nature of God. I would submit that you don't know the nature of God because you haven't bothered to study and show yourself approved. And your hole digging is evidence of it. You just keep digging deeper and deeper with no idea where you're going.