The first saying of Jesus which is preserved to us.
Must (δεῖ)
Lit., it is necessary, or it behoves. A word often used by Jesus concerning his own appointed work, and expressing both the inevitable fulfilment of the divine counsels and the absolute constraint of the principle of duty upon himself. See Mat 16:21; Mat 26:54; Mar 8:31; Luk 4:43; Luk 9:22; Luk 13:33; Luk 24:7, Luk 24:26, Luk 24:46; Joh 3:14; Joh 4:4; Joh 12:34.
About my Father's business (ἐν τοῖς τοῦ πατρός)
Lit., in the things of my Father. The words will bear this rendering; but the Rev. is better, in my Father's house. Mary's question was not as to what her son had been doing, but as to where he had been. Jesus, in effect, answers, “Where is a child to be found but in his Father's house?“