It sounds like you’re describing the idea that the Eucharist (Communion) was like a “will/testament” where Jesus authorized his followers to consume his body rather than bury it.

A couple important corrections/clarifications, though:

The Eucharist is not a literal last will that permits bodily consumption. In Christian theology, it’s a sacrament—a ritual remembrance and participation in Christ—based on Jesus’ words at the Last Supper (e.g., “this is my body… this is my blood”).
Early Christians didn’t treat it as “permission to prevent decay.” The beliefs and practices around the Eucharist are grounded in worship, covenant/community meaning, and (depending on denomination) doctrines like Real Presence (Catholic/Orthodox/Protestant views differ), not in hygiene or avoiding “rot.”

If you’re asking about the history or original meaning of the phrase “last will and testament” in relation to the Eucharist, tell me which angle you mean:

the religious/theological interpretation,
the historical/academic view of what early Christians thought, or
the linguistic claim about “testament/will” language.

ANYHOO 360: The Eucharist was a last will and testament by ritual that gave permission to Jesus followers to eat his body rather than let it decay or be buried and rot in the ground.}

The Eucharist was a last will and testament by ritual that gave permission to Jesus followers to eat his body rather than let it decay or be buried and rot in the ground.