C. F. Keil and Franz Delitzsch on 1 Chronicles 22:2

1Ch 22:2 Workmen and materials for the building of the temple. - 1Ch 22:2. In order to procure the necessary workmen, David commanded that the strangers in the land of Israel should be gathered together, and, as we learn from 2Ch 2:16, also numbered. הגּרים, the strangers, are the descendants of the Canaanites whom the Israelites had not destroyed when they took possession of the land, but had reduced to bondage (2Ch 8:7-9; 1Ki 9:20-22). This number was so considerable, that Solomon was able to employ 150,000 of them as labourers and stone-cutters (1Ki 5:15.; 2Ch 2:16.). These strangers David appointed to be stone-cutters, to hew squared stones, גזית אבני (see on 1Ki 5:18).