Historic pastoral reading
Parents who love their children train them. Discipline is broader than one method.
Spare the rod, spoil the child.
The exact saying is not in Scripture. The closest text is Proverbs 13:24, which speaks of loving discipline. “Spoil the child” comes from later English usage, not the proverb itself.
Proverbs 13:24
24 One who spares the rod hates his son,
but one who loves him is careful to discipline him.
24 He that spareth his rod hateth his son:
but he that loveth him chasteneth him betimes.
Proverbs pairs love with correction. The point is that refusing to discipline is unloving, not that every form of punishment is required.
Parents who love their children train them. Discipline is broader than one method.
Used as a proof-text that the Bible commands spanking in every case, or as a dismissive slogan with no attention to the surrounding wisdom literature.
The surrounding proverbs keep talking about wisdom, speech, and the fruit of righteousness—not a single parenting technique.