John Gill Commentary 1 Samuel 30:28

"and to them that were in Aroer, and to them that were in Siphmoth, and to them that were in Eshtemoa," — 1 Samuel 30:28 (ASV)

And to [them] which [were] in Aroer
Not Aroer in the tribe of Gad beyond Jordan, where David is never said to be, but some city of this name in the tribe of Judah; the Greek version of (Joshua 15:22) , instead of Adadah, has Arouel:

and to [them] which [were] in Siphmoth ;
which very probably was in the tribe of Judah, though nowhere else mentioned:

and to [them] which [were] in Eshtemoa ;
a Levitical city given to the Levites by the children of Judah, (Joshua 21:14) .