Albert Barnes Commentary 2 Chronicles 2:17

"And Solomon numbered all the sojourners that were in the land of Israel, after the numbering wherewith David his father had numbered them; and they were found a hundred and fifty thousand and three thousand and six hundred." — 2 Chronicles 2:17 (ASV)

The “strangers” were the non-Israelite population of the Holy Land, chiefly the descendants of those Canaanites whom the children of Israel did not drive out.

The policy of bond-service was originally imposed on the Canaanites at the time of the conquest (Judges 1:28, 30, 33, 35) but was discontinued during the period of decline between Joshua and Saul. It is clear that the reimposition of this service was due to David, whom Solomon merely imitated in the arrangements described in these verses.