John Gill Commentary 2 Samuel 13:7

"Then David sent home to Tamar, saying, Go now to thy brother Amnon`s house, and dress him food." — 2 Samuel 13:7 (ASV)

Then David sent home to Tamar
Who perhaps was not in the king's palace, but at her brother Absalom's house, (2 Samuel 13:20) ;

saying, go now to your brother Amnon's house ;
who also had a separate house and equipage, being the king's son, and his eldest son:

and dress him meat ;
such as he may desire, and his stomach will bear.