Jesus uses this question to teach the people. AT: "I will tell you who are really my mother and brothers" (See: [[rc://en/ta/man/translate/figs-rquestion]])
This is a metaphor that means Jesus' disciples belong to Jesus' spiritual family. This is more important than belonging to his physical family. AT: "that person is like a brother, sister, or mother to me" (See: [[rc://en/ta/man/translate/figs-metaphor]])