Our way of thinking is attuned to the Eucharist, and the Eucharist in turn confirms our way of thinking.This appears on p. 205 of vol. 2 of the 1857 edition ed. W. W. Harvey (where it is Adv. haer. IV.xxxi.4), as follows (I have not yet checked SC):
Ἡμῶν δὲ σύμφωνος ἡ γνώμη τῇ εὐχαριστίᾳ, καὶ ἡ εὐχαριστία βεβαιοῖ τὴν γνώμην.
Nostra autem consonans est sententia Eucharistiae, et Eucharistia rursus confirmat sententiam.The immediate context here is an insistence, against the gnostics, on "the hope of the resurrection [of the flesh] to eternity": "our bodies, when they receive the Eucharist, are no longer corruptible", but "partake of life".