Now in those days the advice of Ahithophel was like the consultation of the word of God. Such was the regard that both David and Absalom had for Ahithophel’s advice.
Jewish Publication Society of America Version (JPS1917) - 2 Samuel 16:23 >Now the counsel of Ahithophel, which he counselled in those days, was as if a man inquired of the word of God; so was all the counsel of Ahithophel both with David and with Absalom.