Son, behold your Mother, Mother, behold your Son.
John 19:26 When Jesus therefore saw his mother, and the disciple standing by, whom he loved, he saith unto his mother, Woman, behold thy son! 27 Then saith he to the disciple, Behold thy mother! And from that hour that disciple took her unto his own home.
In context who was that written to?
Christ as her eldest son had the responsibility for his widowed mother. He kept all the law perfectly.. here He kept the law to honor your mother and father, by honoring His mother and making provision for her care..
This has no deeper meaning, no theology or doctrine to be found in those words
"And he answered them, saying, Who is my mother, or my brethren?
And he looked round about on them which sat about him, and said, Behold my mother and my brethren!
For whosoever shall do the will of God, the same is my brother, and my sister, and mother. Mark 3:33-35