What is the meaning of Matthew 12:49?

And he stretched forth his hand toward his disciples, and said, Behold my mother and my brethren! (Matthew 12:49 KJV)

And he stretched forth his hand towards his disciples, and said, Behold, my mother and my brethren! (Matthew 12:49 ASV)

And, stretching out his hand to his disciples, he said, Behold my mother and my brethren; (Matthew 12:49 DBY)

And having stretched forth his hand toward his disciples, he said, `Lo, my mother and my brethren! (Matthew 12:49 YLT)

He stretched out his hand towards his disciples, and said, “Behold, my mother and my brothers! (Matthew 12:49 WEB)

Interlinear

And <kai> he stretched forth <ekteino> his <autos> hand <cheir> toward <epi> his <autos> disciples, <mathetes> and said, <epo> Behold <idou> my <mou> mother <meter> and <kai> my <mou> brethren <adelphos>! (Matthew 12:49 KJV)

Hall’s Explication of Hard Texts

And he stretched forth his hand toward his disciples, and said to the messenger, Behold, you tell me of my mother and near kinsfolk: I do not deny due respects to my parent according to the flesh, and to those which are of my natural and bodily kindred; but I would have you know, that it is the spiritual kindred, that I do most affect and stand upon: these, therefore, that by a true and lively faith are spiritually incorporated into me, these, that do carefully and conscionably give up themselves to the obedience of God my Heavenly Father, these are they, that may justly challenge a holy consanguinity with me; and this conjunction of grace in the soul doth more endear my mother and kinsmen unto me, than all earthly and bodily regards whatsoever.

Philip Doddridge N.T.

And looking round on them that were sitting about him to hear his word, and stretching out his hand with an affectionate regard, especially towards those that were his constant followers and professed disciples, he said, What kindred or relations have I that are nearer to me, or more esteemed than these? Behold my mother and my brethren here. For these that hear the word of God, and practise it, are considered and acknowledged by me as my mother and my brethren: nor do I thus regard these only that are now before me, but I declare the same too of all others of their character; {for} whosoever shall do the will of God, my heavenly Father, even this very person, of whatever place and family and station he be, is regarded by me as my brother, or my sister, or mother: for this pious disposition will render such dearer to me, than any of the bands of natural relation, if separate from real holiness, could possibly do.