וַיִּתֵּ֥ן דָּוִ֛יד לְאָרְנָ֖ן בַּמָּק֑וֹם שִׁקְלֵ֣י זָהָ֔ב מִשְׁקָ֖ל שֵׁ֥שׁ מֵאֽוֹת׃
Also gab David Ornan für den Platz sechshundert Schekel Gold nach Gewicht.
Rashi on I Chronicles
shekels of gold, weighing six hundred but at the end of Samuel (II 24:24), it is written: “for fifty shekels of silver.” How is this possible? He took fifty shekels from each tribe, totaling six hundred shekels, so that all Israel should have a share in the altar.
Metzudat David on I Chronicles
For the place – for all the field around the threshing-floor