“The king
Will answer them.
‘Truly!
I say to you!
Just as you did it
To one of the least
Of these
Who are members
Of my family,
You did it to me.’”
καὶ ἀποκριθεὶς ὁ Βασιλεὺς ἐρεῖ αὐτοῖς Ἀμὴν λέγω ὑμῖν, ἐφ’ ὅσον ἐποιήσατε ἑνὶ τούτων τῶν ἀδελφῶν μου τῶν ἐλαχίστων, ἐμοὶ ἐποιήσατε.
This last judgment section is unique to Matthew. The king, not the Son of Man, answered them (καὶ ἀποκριθεὶς ὁ Βασιλεὺς ἐρεῖ αὐτοῖς) with a solemn declaration (Ἀμὴν λέγω ὑμῖν) that if they did it to the least of his brothers (ἐφ’ ὅσον ἐποιήσατε ἑνὶ τούτων τῶν ἀδελφῶν μου τῶν ἐλαχίστων), they did it to him (ἐμοὶ ἐποιήσατε). Caring for the needy weak brothers of Jesus was also caring for Jesus himself. They were all part of one big happy family.
Eugene Finnegan Bible Project 