Fat lady sit on you.

I saw this in a Maryland movie theater. It was a matinee on New Years Day 1977. I haven't seen it since.

I clearly remember a scene where orphans Jason and Holly are climbing a mountain with Zachariah, and they come across a group of people who treat them meanly.

When the orphans and Zachariah say they need food and a place to sleep, a man in the group of mean people, sounding like a Gunsmoke character, says, "Maybe we would help you if you let that fat lady sit on you." Then it cuts to a mid - shot of an older fat lady who looks a lot like 1940s character actress Jane Darwell. She is laughing along with the other mean people -- laughing at the man's suggestion.