Ponder...

“Some day, and that day may never come,

I would like to call upon you to do me a service in return.”

Yes, you got it correct. It’s “The Godfather”. I watched it again and was overwhelmed again! And these are the lines the Don says to Bonsera (in the first scene) after accepting to help him. The Don never accepts money but friendship for his service. It kept me thinking for a little while!