In his book Jesus of Nazareth the Holy Father Pope Benedict reflects upon the Our Father. One of his most interesting mediations concerns the petition usually translated as give us this day our daily bread.
The word which we render as daily is epiousios in the original Greek. This is an extremely rare word and may in fact have originally been invented by the Evangelist Matthew. It is only its etymology and context that makes us think its meaning might approximate to daily. Pope Benedict says that scholars have isolated two likely meanings for the word. One is what is necessary for existence so the prayer would mean give us today the bread that we need in order to live. The other possibility is that it means bread for the future. Now in the context of the whole message of Jesus that could only mean the bread of the future life, to ask today for the physical bread that we might want to eat tomorrow when we get hungry just isn't a Christian thing to request.
The petition then becomes a Eucharistic petition, something almost all the Church Fathers recognised and that found its way into the Vulgate since St Jerome translated it as Give us this day our supersubstantial bread. And this makes sense when we consider that in the teaching by word and deed of Jesus bread is seldom just bread. He makes the point to Satan that man does not live by bread alone. By multiplying bread in the wilderness He not only feeds the hungry but recalls the manna in the desert and reveals Himself as one greater than Moses. In His discourse in John 6 He reveals Himself as the true bread of heaven and in His last meal with the Apostles He shares that bread, which is Himself, with those who love Him.
So when we pray, give us this day our daily bread, we should recall that we are asking the Father to give us His Son so that we might,quite literally, consume Him for our sanctification and strengthening. And we should be grateful beyond words to know that our Father graciously does just that thing because He loves us so much.