John Chrysostom
God's mercy is so profound that, for the sake of our salvation, He sets aside the exalted expressions that are appropriate to His grandeur.
And he answered: I will go out, and be a lying spirit in the mouth of all his prophets. And the Lord said: Thou shalt deceive, and shalt prevail: go out, and do so.
וַיֹּ֗אמֶר אֵצֵא֙ וְהָיִ֙יתִי֙ לְר֣וּחַ שֶׁ֔קֶר בְּפִ֖י כָּל־נְבִיאָ֑יו וַיֹּ֗אמֶר תְּפַתֶּה֙ וְגַם־תּוּכָ֔ל צֵ֖א וַעֲשֵׂה־כֵֽן׃
One Church Father comments on this verse
God's mercy is so profound that, for the sake of our salvation, He sets aside the exalted expressions that are appropriate to His grandeur.
Passages read together with this verse.