Charles Ellicott Commentary 2 Samuel 13:26

"Then said Absalom, If not, I pray thee, let my brother Amnon go with us. And the king said unto him, Why should he go with thee?" — 2 Samuel 13:26 (ASV)

If not ... let ... Amnon. —Absalom then asks that if the king himself will not come, Amnon, as his eldest son and heir-apparent, may represent him at the feast. David hesitates, but as he could hardly refuse without acknowledging a suspicion which he was unwilling to express, he finally consents.