I read in a certain spiritual work that at the Last Supper the Holy Eucharist returned to being bread only when received by the traitor Judas Iscariot. Is this true?
No, when the bread and wine are consecrated and become the Body, Blood, Soul and Divinity of Jesus Christ, this effects a permanent and substantial change, such that the Body and Blood of Christ will not go back to being something else. Further, there's no reason, biblically or theologically, to hold that the case of Judas would be any different.
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