John Gill Commentary 2 Samuel 19:31

"And Barzillai the Gileadite came down from Rogelim; and he went over the Jordan with the king, to conduct him over the Jordan." — 2 Samuel 19:31 (ASV)

And Barzillai the Gileadite came down from Rogelim
The place of his habitation, to Jordan, see (2 Samuel 17:27);

and went over Jordan with the king to conduct him over Jordan ;
to accompany him over the river, and then take his leave of him.