Hebrews 12:11 Proverbs 29:17
Later on, however, it produces a harvest of righteousness and peace for those who have been trained by it.
Discipline your son, and he well give you peace; he will bring delight to your soul.

Here is discipline bringing peace to both giver and receiver. I’ve always wondered about the phrase “to those who have been trained by it.” Can a rebellious heart refuse to be trained, even though God (or us, as parents) is trying to discipline us? “Willful,” I think the books call those children. And the loving parent persists, refusing to let the willful heart win. But train it, don’t break it.