Calling her children about her, she [the Church] nourishes them with holy milk, that is, with the Infant Word…The Word is everything to a child: both Father and Mother, both Instructor and Nurse. “Eat My flesh,” He says, “and drink My blood.” The Lord supplies us with these intimate nutriments. He delivers over His flesh amd pours out His blood; and nothing is lacking for the growth of His children. O incredible mystery!

The blood of the Word has been also exhibited as milk. Milk being thus provided in parturition, is supplied to the infant; … The Word is all to the child, both father and mother and tutor and nurse.

He says,

Such is the suitable food which the Lord ministers, and He offers His flesh and pours forth His blood, and nothing is wanting for the children’s growth. O amazing mystery! We are enjoined to cast off the old and carnal corruption, as also the old nutriment, receiving in exchange another new regimen, that of Christ, receiving Him if we can, to hide Him within; and that, enshrining the Saviour in our souls, we may correct the affections of our flesh.

But you are not inclined to understand it thus, but perchance more generally. Hear it also in the following way. The flesh figuratively represents to us the Holy Spirit; for the flesh was created by Him. The blood points out to us the Word, for as rich blood the Word has been infused into life; and the union of both is the Lord, the food of the babes— the Lord who is Spirit and Word. The food— that is, the Lord Jesus— that is, the Word of God, the Spirit made flesh, the heavenly flesh sanctified.

Citation: Clement of Alexandria, “The Instructor, Book 1”

Further, the Word declares Himself to be the bread of heaven. For Moses, He says, gave you not that bread from heaven, but My Father gives you the true bread from heaven. For the bread of God is He that comes down from heaven, and gives life to the world. And the bread which I will give is My flesh, which I will give for the life of the world. Here is to be noted the mystery of the bread, inasmuch as He speaks of it as flesh, and as flesh, consequently, that has risen through fire, as the wheat springs up from decay and germination; and, in truth, it has risen through fire for the joy of the Church, as bread baked. But this will be shown by and by more clearly in the chapter on the resurrection. But since He said, And the bread which I will give is My flesh, and since flesh is moistened with blood, and blood is figuratively termed wine, we are bidden to know that, as bread, crumbled into a mixture of wine and water, seizes on the wine and leaves the watery portion, so also the flesh of Christ, the bread of heaven absorbs the blood; that is, those among men who are heavenly, nourishing them up to immortality, and leaving only to destruction the lusts of the flesh.

Thus in many ways the Word is figuratively described, as meat, and flesh, and food, and bread, and blood, and milk. The Lord is all these, to give enjoyment to us who have believed on Him. Let no one then think it strange, when we say that the Lord’s blood is figuratively represented as milk. For is it not figuratively represented as wine?

it is said,

In His own Spirit He says He will deck the body of the Word; as certainly by His own Spirit He will nourish those who hunger for the Word.

Citation: Clement of Alexandria, “The Paedagogus, Book I“

The same blood and milk of the Lord is therefore the symbol of the Lord’s passion and teaching.

Citation: Clement of Alexandria, “The Paedagogus, Book I“, Chapter 6

The Scripture, accordingly, has named wine the symbol of the sacred blood.

Citation: Clement of Alexandria, “The Instructor, Book II“