Matthew Poole and continuators on 2 Samuel 15:12

12 And Absalom sent for Ahithophel the Gilonite , Davids Counsellor, from his city, even from Giloh, while he offered sacrifices : and the conspiracy was strong, for the people increased continually with Absalom.

Who is thought to have been the Author, or, at least, the fomenter of this Rebellion; either, because he was discontented with David, for which there might be many reasons; or, because he saw the Father was old and nigh his end, and he thought it best policy to worship the rising Sun, and to follow the young Prince, whom he observed to have so great an interest in the hearts of the people, and whom he supposed he could easily manage as he pleased, which he could not do with David.

Which he did not in Devotion to God, for he neither feared God, nor reverenced Man; nor to implore Gods favour and assistance against his Father, which he knew was a vain thing to expect; but meerly that upon this pretence he might call great numbers of the people together, whereof many would come to join with him in the Worship of God, and most to partake of the Feasts which were made of the remainders of the Sacrifices, according to the manner.