Sing for (one's) supper American British old-fashioned
To gain the benefit or reward by working or providing a service
If you work hard and diligently, I will sing for my supper by signing the internship confirmation for you.
I allow you to shelter here for three days, but you have to sing for your supper by watering the rose field every morning and late afternoon.
I wanted my friend to pay for the meal, but he said I had to sing for my supper by helping him complete his assignments.
The verb "sing" should be conjugated according to its tense.
This metaphoric term alludes to wandering minstrels who performed in taverns and were paid with a meal. First recorded in 1609, it gained currency with the familiar nursery rhyme, “Little Tommy Tucker, sings for his supper” (c. 1744).
A problem or difficult circumstance
I'm short-sighted, so forgetting my glasses is a real hair in the butter for my sight.