וַיִּתֵּ֥ן דָּוִ֛יד לְאָרְנָ֖ן בַּמָּק֑וֹם שִׁקְלֵ֣י זָהָ֔ב מִשְׁקָ֖ל שֵׁ֥שׁ מֵאֽוֹת׃
Also gab David Ornan für den Platz sechshundert Schekel Gold nach Gewicht.
Rashi
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
For the place – for all the field around the threshing-floor