cellio | parsha bit: Va'eira

The rabbis are troubled by God hardening Paro's heart after each plague. How, Rabbi Yochanan asks, did Paro have free will and thus warrant punishment? Rabbi Shimon ben Lakish (Resh Lakish) answers that after the first five plagues Paro hardened his heart and then after the next five God did so. The plagues were warnings and Paro was given five chances to relent. When he didn't, God sent five more as punishment. (Exodus Rabbah 13:3)