1On the third day a wedding took place at Cana in Galilee. Jesus' mother was there, 2and Jesus and his disciples had also been invited to the wedding. 3When the wine was gone, Jesus' mother said to him, "They have no more wine."
Mary simply takes it as a given that this is something Jesus can fix. What has he been doing at home for the past 30 years?
4"Dear woman, why do you involve me?" Jesus replied, "My time has not yet come."
"Mom! Not now!"
5His mother said to the servants, "Do whatever he tells you."
Notice that she doesn't get into any sort of debate with Jesus. She assumes that he'll be a dutiful son and attend to the problem his mother brought to him.
Then she tells the servants, in essence, "Whatever weird, inexplicable instuctions you get, follow them." This speaks to prior experience with Jesus taking care of situations in a miraculous way.
Though the rest of the story is the part people focus on, to me the main thing it does is illustrate what went before -- that Jesus had been doing miracles behind closed doors for his family long enough that his mother took it as a given that he could -- and would -- fix things.
And I guess, given how trivial those matters must have been -- running out of wine at a wedding feast is a social gaffe, hardly on a par with demon possession, or being deaf or lame or blind or dead. But it's as if nothing is too small to capture Jesus' attention if we bring it to him.
6Nearby stood six stone water jars, the kind used by the Jews for ceremonial washing, each holding from twenty to thirty gallons.[a]
7Jesus said to the servants, "Fill the jars with water"; so they filled them to the brim.
8Then he told them, "Now draw some out and take it to the master of the banquet."
They did so, 9and the master of the banquet tasted the water that had been turned into wine. He did not realize where it had come from, though the servants who had drawn the water knew. Then he called the bridegroom aside 10and said, "Everyone brings out the choice wine first and then the cheaper wine after the guests have had too much to drink; but you have saved the best till now."
11This, the first of his miraculous signs, Jesus performed in Cana of Galilee. He thus revealed his glory, and his disciples put their faith in him.