‘What is zazen good for? Nothing! We should be made to hear this good-for-nothingness so often that we get calluses on our ears and practice good-for-nothing zazen without any expectation. Otherwise, our practice really is good for nothing.’ (The Zen Teaching of Homeless Kodo)

I may have used this quote before. I was wondering about going and checking, but then thought that even if I had, it is worth hearing again and again, just as Sawaki Roshi says. Uchiyama Roshi, in his commentary, mentions how frequently Sawaki Roshi used this phrase, and we have to keep underlining that expectation is alien to true zazen, however much we might pine for benefits.