In the Rashi on 53a, Rashi translates "which word" (do we use to learn out sekila in the gezera shava), in many prints of the Gemara, into "aizeh tova", which apparently makes no sense.

Rav Dovid Cohen, in his "he'akov lemishor" mentions this as one case of where the proofreader read the words out loud that he was proofreading, to the typesetter. So, he read "aizeh, teiva", meaning which word, and the one listening to him (a certifiable Litvak, obviously), heard it as.....tova!

Gershon

gershon.dubin@juno.com