en_tn/jhn/19/26.md

the disciple whom he loved

This is John, the writer of this Gospel.

Woman, see, your son

Here the word "son" is a metaphor. Jesus wants his disciple, John, to be like a son to his mother. Alternate translation: "Woman, here is the man who will act like a son to you" (See: rc://en/ta/man/jit/figs-metaphor)