“Hold your horses” may come to English via Homer.
I learned this while reading Emily Wilison’s Iliad translation published in 2023. Near the end of the book, it has:
[....] Antilochus!
Your driving is too reckless! Hold your horses!
This track is narrow. It will widen soon
and then the chariots can pass. Do not
smash into me or you will hurt us both.
This struck me as absurd and anachronistic when I read it. However, it may be the ultimate source of the idiom in English!
A number of explanations, all unverified, have been offered for the origins of the phrase, dating back to usage in Ancient Greece. [....] In Book 23 of the Iliad, Homer writes "Hold your horses!" when referring to Antilochus driving like a maniac in a chariot race that Achilles initiates in the funeral games for Patroclus.