שָׁ֣לַֽח חֹ֭שֶׁךְ וַיַּחְשִׁ֑ךְ וְלֹֽא־מָ֝ר֗וּ אֶת־דברוו [דְּבָרֽוֹ׃]
Il répandit des ténèbres qu’il rendit impénétrables, pour qu’ils ne résistassent pas à sa parole.
Rashi on Psalms
And they did not disobey His word The plagues, that He commanded upon them, came according to His commandments and did not deviate from His word.