Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Third Ecumenical Council:  The Council of Ephesus.: Anathematism XI

XI.

Whosoever shall not confess that the flesh of the Lord giveth life and that it pertains to the Word of God the Father as his very own, but shall pretend that it belongs to another person who is united to him [i.e., the Word] only according to honour, and who has served as a dwelling for the divinity; and shall not rather confess, as we say, that that flesh giveth life because it is that of the Word who giveth life to all:  let him be anathema.

Notes.

Nestorius.

XI.

If any one maintains that the flesh which is united with God the Word is by the power of its own nature life-giving, whereas the Lord himself says, “It is the Spirit that quickeneth; the flesh profiteth nothing” (John 6.61), let him be anathema.  [He adds, “God is a Spirit” (John 4.24).  If, then, any one maintains that God the Logos has in a carnal manner, in his substance, become flesh, and persists in this with reference to the Lord Christ; who himself after his resurrection said to his disciples, “Handle me and see; for a spirit hath not flesh and bones, as ye behold me having” (Luke 24.39); let him be anathema.]

Hefele.

The part enclosed in brackets is certainly a spurious addition and is wanting in many manuscripts.  Cf. Marius Mercator [ed. Migne], p. 919.

St. Cyril.

(Declaratio undecima.)

We perform in the churches the holy, lifegiving, and unbloody sacrifice; the body, as also the precious blood, which is exhibited we believe not to be that of a common man and of any one like unto us, but receiving it rather as his own body and as the blood of the Word which gives all things life.  For common flesh cannot give life.  And this our Saviour himself testified when he said:  “The flesh profiteth nothing, it is the Spirit that giveth life.”  For since the flesh became the very own of the Word, therefore we understand that it is lifegiving, as the Saviour himself said:  “As the living Father hath sent me, and I live by the Father; so he that eateth me shall live by me.”  Since therefore Nestorius and those who think with him rashly dissolve the power of this mystery; therefore it was convenient that this anathematism should be put forth.