And the stones shall be with the names of the children of Israel, twelve, according to their names, like the engravings of a signet; every one with its name shall they be according to the twelve tribes.
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Ambrose of Milan
AD 397
Of these twelve, as of twelve precious stones, is the pillar of our faith built up. For these are the precious stones—sardius, jasper, smaragd, chrysolite, and the rest—woven into the robe of holy Aaron, even of him who bears the likeness of Christ, that is, of the true Priest. [These] stones [are] set in gold and inscribed with the names of the sons of Israel, twelve stones close joined and fitting one into another, for if any should sunder or separate them, the whole fabric of the faith falls in ruins. On the Christian Faith , introduction
And on the breast of the high priest were certain stones hanging, twelve in number, in the midst of which were placed two other stones, manifestation and truth. By means of a riddle through these the chorus of the holy apostles is clearly signified being, as it were, in a circle around Emmanuel, who is manifestation and truth. For he manifested the truth by having taken away the worship of God in shadows and in types.
But why was it that [Christ] chose twelve apostles, and not some other number? In truth, I might from this very point conclude of my Christ that he was foretold not only by the words of prophets but by the embodied language of facts. For of this number I find figurative hints up and down the Creator’s dispensation in the twelve springs of Elim; in the twelve gems of Aaron’s priestly vestment; and in the twelve stones appointed by Joshua to be taken out of the Jordan and set up for the ark of the covenant. –.