L. M. Grant's Commentary on the Bible - 2 Samuel 17:1-29
Ahithophel discerned clearly that if Absalom was to gain any victory over David he must strike quickly. Satan knows that the only way to establish the anti-christ in power is to destroy the true Christ. So Ahithophel urges that he be allowed to take with him 12,000 men (in contrast to the few hundred who had gone with David) and immediately the same night pursue David. He well reasons that such an attack would scatter David's men and leave David unprotected, so that they could kill him alone.... read more
Geneva Study Bible - 2 Samuel 17:21
17:21 And it came to pass, after they were departed, that they came up out of the well, and went and told king David, and said unto David, Arise, and pass quickly over the water: for {k} thus hath Ahithophel counselled against you.(k) That is, to pursue you with all haste. read more