St. Matthew (28:16–20) records the appearance that closes his Gospel. The Eleven disciples went to Galilee, to the mountain Jesus had appointed for them. 'And seeing him they adored: but some doubted.' Jesus drew near and spoke the words known as the Great Commission: 'All power is given to me in heaven and in earth. Going therefore, teach ye all nations; baptizing them in the name of the Father, and of the Son, and of the Holy Ghost. Teaching them to observe all things whatsoever I have commanded you: and behold I am with you all days, even to the consummation of the world.'
These are the last words of Christ in Matthew's Gospel. They establish the Church's three principal acts: to teach, to baptize, and to make disciples of all nations. The closing promise — 'I am with you all days, even to the consummation of the world' — is the perpetual presence of Christ in His Church through Word and Sacrament until the end of time.
The location is traditionally identified with the Mount of Beatitudes above Tabgha, the same mountain where Christ had given the Sermon on the Mount at the beginning of His public ministry. The first hill of His public teaching becomes the last hill of His earthly presence.