As saith the proverb of the ancients
It is an old saying, has been long in use, and may be applied to the present case; or the "proverb of the ancient one"; of the oldest man, the first man Adam, and of all others after him, so Kimchi; or of the Ancient One of the world, the Ancient of days, the Lord himself; so in the Talmud F4: wickedness proceedeth from the wicked;
as is a man, so are his actions; if he is a wicked man, he will do wicked things; a corrupt tree brings forth evil fruits, an evil man out of the evil treasure of his heart brings forth evil things; and as if David should say, if I had been the wicked man as I am represented, I should have committed wickedness; I should have made no conscience of taking away thy life when it was in my power; but my heart would not suffer me to do it: but,
or "and" my hand shall not be upon thee;
as it has not been upon thee, because of the fear of God in me, so neither shall it be hereafter: or the sense of the proverb may be, the wickedness that comes from a wicked man, that will kill him, or be the cause of his ruin, or he will be slain by wicked men such as himself; and this may be thy case, O king, unless thou repentest: but be that as it may, which I leave with the righteous Judge, this I am determined on, "mine hand shall not be upon thee"; to take away thy life.