Charles Ellicott Commentary 2 Samuel 15:26

"but if he say thus, I have no delight in thee; behold, here am I, let him do to me as seemeth good unto him." — 2 Samuel 15:26 (ASV)

Let him do to me as seemeth good. —David recognizes that he is suffering under the punishment pronounced by Nathan for his sin, and he seeks to throw himself entirely into the hands of God, trusting in His mercy. (Compare to 2 Samuel 24:14) He is, therefore, unwilling to have the ark carried with him lest he should seem to undertake to compel the Divine presence and blessing. He feels sure that if God so wills, he will be brought back in peace; but if not, yet he will perfectly submit himself to God’s ordering.