Augustine of Hippo — as excerpted in the Catena Aurea on John 21:1-11

“(Tract. cxxii) It is not then signified that only a hundred and fifty-three saints are to rise again to eternal life, but this number represents all who partake of the grace of the Holy Spirit: which number too contains three fifties, and three over, with reference to the mystery of the Trinity. And the number fifty is made up of seven sevens, and one in addition, signifying that those sevens are one. That they were great fishes too, is not without meaning. For when our Lord says, I came not to destroy the law, but to fulfil, by giving, that is, the Holy Spirit through Whom the law can be fulfilled, He says almost immediately after, Whosoever shall do and teach them, the same shall be called great in the kingdom of heaven. In the first draught the net was broken, to signify schisms; but here to shew that in that perfect peace of the blessed there would be no schisms, the Evangelist continues: And for all they were so great1, yet was not the net broken; as if alluding to the case before, in which it was broken, and making a favourable comparison.”