In this case, the sign and the message are separated by a couple of days. Jesus and his disciples are out in the country, away from any villages. And they are being followed by a large crowd of people.
Jesus says, “The people are hungry. We need to feed them.” The disciples say, “We don’t have enough food. We don’t have enough money to buy enough food. And the only food we do have is this little boy’s lunch.”
So, Jesus borrows the little boy’s lunch, and feeds 15-20,000 people with it. Then, the disciples clean up afterward, and collect 20 times as much food in leftovers, as they started with.
The crowd starts thinking: “If we mad Jesus King, we wouldn’t have to work anymore.” Jesus, knowing his mission (which was not being king), sneaks away into the mountains, and eventually, takes a boat across a nearby lake.
The crowd wanders around looking for him, and, eventually, crosses the same lake. When they find Jesus, he begins his teaching.
He questions their motives. They did not understand the signs, their meaning, nor their significance. They are only looking for him, because their bellies are full.
They were short-sighted. Meeting their basic needs was important; but they were only focused on meeting their basic needs. They were not focused on their relationship with the Father.
God sent the Promised One to give people a way to re-connect, and re-establish a relationship with him. Jesus used a metaphor, comparing bread and allegiance with him. Coming to Jesus, giving allegiance to him, and choosing to follow him, results in receiving life from the God-head. He gives life, when we give allegiance, by satisfying the requirements of the Law, redeeming the person from Satan’s kingdom, and moving the person into God’s family.
He also gives life, when we follow him by providing necessary spiritual fuel. We have fellowship with the Father, who pours his love and grace into our hearts. (People need love.) We are joined to his family. (People need community.) And he enables us to live our purposes. (People need purpose. And, he uniquely made each person to fill a niche in the universe.)
Knowing Jesus is like eating bread, that provide nutrients no other food provides. Without this bread, we will eventually starve. With this bread, we live, but more, we thrive.