Jerome
Catena Aurea · Matthäusevangelium 12
While he yet talked to the people, behold, his mother and his brethren stood without, desiring to speak with him. Then one said unto him, Behold, thy mother and thy brethren stand without, desiring to speak with thee. But he answered and said unto him that told him, Who is my mother? and who are my brethren? And he stretched forth his hand toward his disciples, and said, Behold my mother and my brethren! For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.
(in loc.) But some suspect the brethren of the Lord to be sons of Joseph by another wife, following the idle fancies of apocryphal writers, who have coined a certain woman called E sea. But we understand by the brethren of the Lord, not the sons of Joseph, but cousins of the Saviour, sons of a sister of Mary, an aunt of Our Lord, who is said to be the mother of James the Less, and Joseph, and Jude, whom in another place of the Gospel we find called the brethren of the Lord. (Mark 6:3) And that cousins are called brethren, appears from every part of Scripture.