Should one find a man who points out faults and who reproves,
let him follow such a wise and sagacious person
as one would a guide to hidden treasure.
It is always better, and never worse,
to cultivate such an association.

- DhammaPada Verse 76

I shall not mollycoddle you like a potter with their damp, unfired pots.

- Excerpt from MN 122

The Buddha is emphasising on the quality of a teacher who is pointing out faults, who reproves. This is said primarily with respect to the wrong views a student might be holding on to.

An enlightened being would be always polite, friendly, respectful maintaining harmony in their relationships. Even in a teacher-student relationship, an enlightened being would not be angry, or show ill-will, aversion, or hostility; as these are the qualities of an unEnlightened mind. By the time one gets to enlightenment, these are fully purified.

Related Teachings:

• Investigate the Teacher Himself (MN 47) ↗️ - The Buddha shares an extensive way to check for if a teacher has defilements, and how a student can gauge that they are learning from a wise teacher.
• Navigating through 30 mental qualities that lead to enlightenment - Being easy to correct is an important quality a student should cultivate, for it opens up the possibility of growth in the teachings.