TLIK: “I wonder the source of your Torah. Firstly, tell me where it says to give petch? It is not included among the 613 Mitzvos, not according to the Rambam, Ramban, Sefer Hachinuch, and Shulchan Aruch does not give any such mitzvah.”
Is this pasuk missing from your Tanach (Mishlei 13:24)?: חוֹשֵֹ֣ךְ שִׁ֖בְטוֹ שׂוֹנֵ֣א בְנ֑וֹ וְ֜אֹהֲב֗וֹ שִֽׁחֲר֥וֹ מוּסָֽר:
Is your Shulchan Aruch missing Orach Chayim 551:18? The Shulchan Aruch makes a special point to say not to hit children during “the three weeks” between the 17th of Tammuz and Tisha Bi’Av. This makes clear that parents and teachers, when appropriately hitting the rest of the year, is to be for the purpose of education. The Shulchan Aruch says not to hit like an enemy nor to hit cruelly; the adult should hit the child with a small strap (Yorah Daya 245:10). Pischai Tshuva on this expands further on how to hit a child.
Ashkenazim do permit hitting a child till the age of twenty two. However several complex issues enter the question after the child is bar/bas mitzva [Yora Daya 240:19-20, Rama, Pischay Tshuva and Birchay Yosef and Rambam Dayos]. Hitting a child over bar/bas mitzva would be a possible option only if it is for the pure sake of chinuch. The parent must make an objective evaluation of the child’s nature. The hitting is not allowed if the child is married.