Proverbs 22:15 Spare the rod, and you will spoil the child.
No loving parent wants to see their child suffer or experience pain. We hurt when they hurt! However, a wise parent understands that without proper discipline, their child WILL hurt themselves and others. True love corrects and punishes despite the pain it may cause.
"Now no chastening seems to be joyful for the present, but painful; nevertheless, afterward it yields the peaceable fruit of righteousness to those who have been trained by it." Hebrews 12:11