Alcuin
Catena Aurea · Johannesevangelium 2
Joh 2, Verses 12–13English original
After this he went down to Capernaum, he, and his mother, and his brethren, and his disciples: and they continued there not many days. And the Jews’ passover was at hand, and Jesus went up to Jerusalem.
Our Lord’s brethren are the relations of Mary and Joseph, not the sons of Mary and Joseph. For not only the blessed Virgin, but Joseph also, the witness of her chastity, abstained from all conjugal intercourse.