Let me just tack a few things on to your fine comments, Mike.
In addition to what you said about the economic of the time, a first century Jew listening to Rabbi Jesus could not hear him speak of “daily bread” without immediately thinking of Exodus 16 and the manna given to the Jews during their wandering in the Sinai desert. God provides the Jews with manna each day and instructs them to take no more than a single day’s portion (with an exception made for Friday when they are to take two day’s portion so as not to have to gather manna on the Sabbath).
As is always the case someone has to test the rule. Someone ignores the rules and gathers a double portion hoping to secure enough by taking more than enough. In the morning, however, his left over manna is teeming with worms. The Torah’s message, carried by Jesus in his prayer, is to live with enough.
The Lord’s Prayer calls the Jews back to Sinai. He is challenging them to surrender to God once again, and to trust that God will lead us to where we need to be and sustain as we journey there. He is saying, “The treasures we store up for ourselves cannot sustain us. Tomorrow they will be as rotten as the illicit portion of manna. God provided for us in Sinai and God will provide for us now, but only if we learn to live within the confines of enough.”
There is enough for all if each takes only enough. Most of us, however, take more than enough, or at least desire to do so. We imagine (wrongly) that life is a zero-sum game where my abundance depends on another’s lack, so we pursue more than enough fearful that if we don’t someone else will take our portion as well as their own. It is grasping for more than enough that is at the root of most if not all of the world’s suffering. And it is here that Jesus use of “us” comes in.
First we should remember that Jewish liturgy is intrinsically communal. We almost always speak in the first person plural rather than the first person singular. Second Jesus is again reminding us of Sinai where there was enough for all of us as long as each of us took no more than we needed.
The challenge of course is to trust that this is so. Few of us do. We are always seeking that extra portion of manna expecting that this time it will not rot. As the economy has recently reminded us, there is no security in stored up treasure.