Exodus 32:12

לָמָּה יֹאמְרוּ מִצְרַיִם לֵאמֹר בְּרָעָה הוֹצִיאָם לַהֲרֹג אֹתָם בֶּהָרִים וּלְכַלֹּתָם מֵעַל פְּנֵי הָאֲדָמָה שׁוּב מֵחֲרוֹן אַפֶּךָ וְהִנָּחֵם עַל הָרָעָה לְעַמֶּךָ

Why should the Egyptians speak, saying, “He brought them forth for evil, to slay them in the mountains and to consume them from the face of the earth?” Turn from Your fierce wrath and repent of this evil against Your people.”

This verse is cited in the long form of Tachanun. Onkelos generally removes human characteristics attributed to G-d from his Aramaic translation in order to keep people from taking them too literally. “Repent” suggests that G-d is capable of regretting His decisions. Accordingly, Onkelos changes it to “Turn from Your fierce wrath and turn away from the evil that you thought to do to Your people.”