וַתִּשְׁקֹ֥ט הָאָ֖רֶץ אַרְבָּעִ֣ים שָׁנָ֑ה וַיָּ֖מָת עָתְנִיאֵ֥ל בֶּן־קְנַֽז׃ (פ)
И земля отдыхала сорок лет. И умер Гофонил, сын Кеназа.
Metzudat David on Judges
AND IT WAS QUIET: By this, the land was quiet and rested from war until the end of the forty years from the time of the beginning of the slavery as its written in Seder Olam