While defending Transubstantiation (which requires a virtual presence of the body, blood, soul, and divinity of Jesus after the words of consecration), two Catholics noted that:
. . . the copula “to be” (GK: εστιν) by itself does not require
a literal translation. To understand the meaning of “is” in this context
better, we have to turn to the underlying Aramaic and the context of the
passage.
The underlying Aramaic that Jesus
used at the Last Supper is speculative but largely agreed upon by biblical
scholars, Catholics and non-Catholic alike. Through an analysis of the Greek text,
Jesus likely pronounced the words dēn biśrî (literally, “this is my body”) and dēn
‘idmî (literally, “this, my blood”) over the bread and wine respectively. The
Greek is a faithful translation of this Aramaic wording. While this construction
in Aramaic can be interpreted as literal, it does not entirely dismiss the
possibility of a figurative understanding of the text. (Stacy Trasancos
and George Elliott, Behold, it is I: Scripture, Tradition, and Science on
the Real Presence [Gastonia, N.C.: TAN Books, 2021], 37-38)