Understand that man does not live on bread alone but that man lives on everything that comes from the mouth of God
The famous words of Moses at the end of the first reading (Deut 2:2-3,14-16) become the anchor on which, John especially, develops a Eucharistic theology. From this I take a particular importance of life and bread but also of the mouth.
Living in a land obsessed with water and the beach life we often see at beaches flags between which we should swim. This is the patrolled area of the beach where if one is swimming is watched by the surf lifesavers: mostly volunteers who are well trained in many aspects of the beach conditions and first aid. We Aussies know that swimming in the safety areas we are watched and have a stronger likelihood of surviving any danger that comes our way (and there are few dangers in the waters of Australia!). It is not uncommon to see in times of need the often life-saving technique of mouth-to-mouth resuscitation.
Returning to scripture John the Evangelist opens his gospel with “the word of God made flesh” prologue. This prologue is expounded throughout his gospel, and not more-so than in the 6th chapter from where we get this weeks gospel. Jesus equates himself as the bread come down from heaven – the manna given by God in the desert. Jesus becomes the Word made flesh, the word of God which comes from his mouth, that which we must eat to live.
We need everything that comes from the mouth of God to live: words come from the mouth: Jesus is the word of God made flesh: Jesus gives us his flesh to eat: it is his flesh which we must eat to gain eternal life: gaining eternal life he lives in us and we in him. This unifies us in Christ, a true communion.
Coming from the mouth of God and us receiving God in our mouths Jesus brings the gift of life to us. Through him we are revived in a deadly environment – and there are quite a few dangers in the water. He is the one who watches over us, who revives us, who volunteers himself for us. He freely gives us himself, yes, but we must freely receive him; mouth to mouth.