הלכה על ראש השנה 35:4

And the proof to these words of ours is that which they said (Rosh Hashanah 18a) concerning a [Divine] decree that has an oath with it, as Rava concludes there, that it is not atoned with a sacrifice or a grain offering, but rather it is atoned with words of Torah; and they have no mention there that God would need to annul [His oath]. As the matters are known and clear to all who see the sun that it is all said metaphorically for the receivers. And in order to direct you on this path in many places, I have been lengthy about this until now.