Not even in Augustine is there any "'symbolism' in the strict sense of a sign independent of the . . . reality for which it stands"

"The bread and wine are not a figure of the body and blood of Christ—God forbid!—but the actual deified body of the Lord, because the Lord himself said:  'This is my body'; not 'a figure of my body' but 'my body,' and not 'a figure of my blood' but 'my blood.'  Even before this He had said to the Jews:  'except you eat of the flesh of the Son of man and drink his blood, you shall not have life in you.  For my flesh is meat indeed:  and my blood is drink indeed.'  And again:  'He that eateth me shall live.' . . .

"Wherefore, in all fear and with a pure conscience and undoubting faith let us approach, and it will be to us altogether as we believe and do not doubt.  And let us honor it [sc. the body and blood of Christ] with all purity of body and soul, for it is twofold.  Let us approach it with burning desire, and with our hands folded in the form of a cross let us receive the body of the Crucified.  With eyes, lips, and faces turned toward it let us receive the divine burning coal, so that the fire of the coal may be added to the desire within us to consume our sins and enlighten our hearts, and so that by this communion of the divine fire we may be set afire and deified. . . .

"It is Christ’s body and blood entering into the composition of our soul and body [(εἰς σύστασιν τῆς ἡμετέρας ψυχῆς τε καὶ σώματος χωροῦν)] without being consumed, without being corrupted, without passing into the privy—God forbid!—but into our substance for our sustenance [(εἰς τὴν ἡμῶν οὐσίαν τε καὶ συντήρησιν)], a bulwark against every sort of harm and a purifier from all uncleanliness—as if He were to take our adulterated gold and purify it by the discerning [purifying] fire, 'so that in the life to come we shall not be condemned with the world.'"

     St. John of Damascus, Expositio fidei 86 (PTS 12 (1973, ed. Kotter), 195.114-120; 196.121-129, 143-148), trans. Christoph Markschies in "Current research on the Eucharist in ancient Christianity:  how the Eucharist developed from the end of the fourth century in East and West," Early Christianity 7 (2016):  434 (417-446).  There is so much more to be pulled from this, e.g., from pp. 443-444:

To assess Augustine's theses through the prism of medieval and Reformation controversies between proponents of 'realistic' and more 'symbolic' eucharistic doctrines would be to completely misunderstand him.  For our Church Father, all reality is only comprehensible to man on earth through signs. . . .  In Augustine there is no 'symbolism' in the strict sense of a sign independent of the corollary reality for which it stands.