Having a look at the Richard Stallman entry in Wikipedia[0] it menions this quote you're referring to, which links to this Engadget article[1] that links to rms's blog with that specific entry[2]

[0] - https://en.wikipedia.org/wiki/Richard_Stallman

[1] - https://www.engadget.com/2019-09-17-rms-fsf-mit-epstein.html

[2] - https://stallman.org/archives/2019-jul-oct.html#14_September...