Here are some Pain quotes from Naruto that I found:

- "Sometimes you must hurt in order to know, fall in order to grow, lose in order to gain because life’s greatest lessons are learned through pain."
- "Knowing pain is essential...for growth."
- "The cycle of hatred can never be broken...and wars will never cease."
- "The true measure of a shinobi is not how he lives but how he dies. It’s not what they do in life but what they did before dying that proves their worth."

I hope this helps!