The altar corresponds to the holy tomb of Christ. On it Christ brought Himself as a sacrifice to [His] God and Father through the offering of HIs body as a sacrificial lamb, and as high priest and Son of Man, offering and being offered as a mystical and bloodless sacrifice, and appointing for the faithful reasonable worship, through which we have become sharers in eternal and immortal life. ~Saint Germanus
This quote represents another reason why I love the Church Fathers. They wrote with such clarity. No ambiguity. Find more excellent quotes from this Saint and images like the one above here.