לְאַרְבַּ֨ע רוּח֜וֹת מְדָד֗וֹ ח֤וֹמָה לוֹ֙ סָבִ֣יב ׀ סָבִ֔יב אֹ֚רֶךְ חֲמֵ֣שׁ מֵא֔וֹת וְרֹ֖חַב חֲמֵ֣שׁ מֵא֑וֹת לְהַבְדִּ֕יל בֵּ֥ין הַקֹּ֖דֶשׁ לְחֹֽל׃
אױף פֿיר זײַטן האָט ער עס אָפּגעמאָסטן; עס האָט געהאַט אַ מױער רונד אַרום, די לענג פֿינף הונדערט, און די ברײט פֿינף הונדערט כּדי אָפּצושײדן צװישן הײליקן און אומהײליקן.
Bartenura
The Temple Mount was five hundred cubits. It was enclosed by a wall
English Explanation of Mishnah Middot
The Temple Mount was five hundred cubits by five hundred cubits. This accords with the dimensions stated in Ezekiel 42:20.
Rashi
And with this measurement [lit. from this measurement.] With the measuring rod by which the 500 by 500 square of the Temple Mount was measured, as is stated above (42:20): “To four sides he measured it; its wall all around, five hundred rods, etc.”