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
Well, if He kept the law perfectly, then He would have left His Mother to those "brothers and sisters" that the "Reformed" insist He had.
Yet, we hear Christ saying earlier,
“For whoever does the will of my Father in heaven is my brother and sister and mother.”
Thus Mary is our mother too.
He'd better be her only child, then, not her eldest child, because otherwise he's sinning by excusing another Jew from obedience to Torah. (Well, I suppose all of his alleged younger siblings could be already dead ... but that seems far-fetched.)