2 Samuel 16:21

And Ahithophel said unto Absalom,.... Either immediately of himself, without consulting with others; or after a consultation had been held between them, he as the president of it, and their mouth, gave the following advice; though the former seems most correct:go in unto thy father's concubines, which he hath left, to keep the house; and lie with them; there were ten of them, 2Sa 15:16;and all Israel shall hear that thou art abhorred of thy father; this fact will be so abominable to him, and he will so highly resent it, as never to forgive thee, and be reconciled unto thee:then shall the hands of all that [are] with thee be strong; he intimates that they were now weak, and did not act with spirit; they were fearful that David and Absalom would be reconciled, and then they should be reckoned traitors, and fall a sacrifice to David's vengeance, for their treason against him: but by Absalom's taking such a step as this, which would make him for ever the object of his father's hatred, their hands and hearts would be strengthened, and their fears removed, and they would not have the least jealousy of a reconciliation between them, and of their being left to the resentment of David.