watched upon the evil - expressing ceaseless vigilance that His people’s sins might not escape His judgment, as a watchman on guard night and day (Job 14:16; Jer 31:28; Jer 44:27). God watching upon the Jews’ punishment forms a striking contrast to the Jews’ slumbering in their sins.
God is righteous - True penitents “justify” God, “ascribing righteousness to Him,” instead of complaining of their punishment as too severe (Neh 9:33; Job 36:3; Psa 51:4; Lam 3:39-42).