What the Bible says about punishment

Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me. (Psalm 23: 4)

Blessed is the man whom thou chastenest, O Lord, and teachest him out of thy law; (Psalm 94: 12)

My son, despise not the chastening of the Lord; neither be weary of his correction:

For whom the Lord loveth he correcteth; even as a father the son in whom he delighteth. (Proverbs 3: 11-12)