There with them; not in Jerusalem, but in a place near to it, to which they could easily send upon occasion. See 2 Samuel 17:17.
Related Commentaries of 2 Samuel 15:36
2 Samuel 15:36
36 Behold, they have there with them their two sons, Ahimaaz Zadok's son, and Jonathan Abiathar's son; and by them ye shall send unto me every thing that ye can hear.