John Gill Commentary 1 Kings 22:16

"And the king said unto him, How many times shall I adjure thee that thou speak unto me nothing but the truth in the name of Jehovah?" — 1 Kings 22:16 (ASV)

And the king said to him, how many times shall I adjure
you
Not that he has as yet adjured him at all, or not till now; but he asks him how often he must be obliged to do it; and now he adjures him once for all, that he might not be forced to repeat it:

that you tell me nothing but that which is true in the name of the
Lord ?
for he observed he did not speak in the name of the Lord before, and what he said was not in a serious but ludicrous manner, and not to be regarded as truth.