Parashas Shemos
וַיִּקַּ֨ח מֹשֶׁ֜ה אֶת־אִשְׁתּ֣וֹ וְאֶת־בָּנָ֗יו וַיַּרְכִּבֵם֙ עַֽל־הַחֲמֹ֔ר וַיָּ֖שׇׁב אַ֣רְצָה מִצְרָ֑יִם וַיִּקַּ֥ח מֹשֶׁ֛ה אֶת־מַטֵּ֥ה הָאֱלֹהִ֖ים בְּיָדֽוֹ׃
So Moses took his wife and sons, mounted them on a donkey, and went back to the land of Egypt; and Moses took the rod of God with him.
Torah Temimah points to Megillah 9a (verified).
על החמור — מעשה בתלמי המלך\ldots וכתבו לו\ldots עַל הַחֲמוֹר.
English: “On the donkey” — the episode of King Ptolemy\ldots and they wrote for him “on the donkey.”
Custom
The verse figures in the tradition of the changes made by the elders for Ptolemy.