For “My child, do not despise the Lord’s discipline or be weary of his reproof, for the Lord reproves the one he loves, as a father the son in whom he delights,” see Hebrews 12:5 and Hebrews 12:6.

Note that this quote in the New Testament is not taken from the Hebrew Bible but from the Greek Septuagint (LXX) which translates into English as “My son, do not belittle the Lord’s discipline nor break down when you are reproved by him; for whom the Lord loves, he disciplines, and he punishes every son he accepts.” (Translation by NETS — for the Greek version see the title’s tooltip)