Bede ( Bede: On the Tabernacle (Liverpool University Press - Translated Texts for Historians) ) neatly contrasts Sinai and the mount of Jesus’ sermon. Moses goes up alone on Sinai “since at that time the Scripture of the law was being committed solely to the people of Israel.” Jesus speaks to apostles and crowds on the mountain because “the grace of the gospel was going to reach all nations throughout the world by the preaching of the apostles.”

Pentecost fits here too: “Nor was it the apostles alone who received the gift of the Spirit by which this same grace-filled truth of the gospel was given more manifestly to the Church, but a very great company of the faithful who were gathered together in an upper room on Mount Zion, and this took place with a distribution of diverse tongues, so that by this particular kind of miracle it might be signified that the Church was going to be praising God in the tongues of all the peoples throughout the world.”