When the children of Israel had been freed from slavery in Egypt by the offering of the paschal lamb, they journeyed through the desert toward the Promised Land, and they reached Mount Sinai.
On the fiftieth day after the Passover, the Lord descended upon the mountain in fire, and with the sound of a trumpet and with thunder and lightning, He gave them the ten commandments of the Law.
[...] We already know that the Passover Lamb and the deliverance from Egypt foreshadow the death of Christ and our deliverance from sin, as it is written: “Christ our Passover Lamb is sacrificed for us” (1 Cor 5:7).
He is “the true Lamb Who has taken away the sins of the world” (John 1:29), Who has redeemed us from the slavery of sin at the price of His blood, and by the example of His resurrection has shown us the hope of life and everlasting liberty.
The Law was given on the fiftieth day after the slaying of the lamb, when the Lord descended upon the mountain in fire; likewise on the fiftieth day after the resurrection of our Redeemer, which is today, the grace of the Holy Spirit, descending in the outward appearance of fire, was given to the disciples as they were assembled in the upper room.
The height of the mountain, and the elevation of the upper room, both indicate the sublimity of the commands and of the gifts.
At the sealing of the first covenant, the people remained at the base of the mountain, a handful of elders went partway up, and only Moses ascended to the summit.
At the sealing of the second covenant, the whole community of God’s people was gathered at the summit, in the upper room.
[...] In the law, the fiftieth year was ordered to be called the Year of Jubilee. During that year, all debts were to be cancelled, all slaves to be set free, the very beasts of burden to be eased from their yokes, and the year given over to celebrating the Divine praises.
Therefore, by this number is rightly indicated the tranquillity of that greatest peace when, at the sound of the trumpet, the dead shall be raised imperishable, and we shall all be changed into glory.
Then, when we are freed from every yoke of sin…the entire company of the people of God will give themselves over to contemplating the Heavenly Vision, and the command of the Lord will be fulfilled: “Be still, and know that I am God.”
The Venerable Bede (672/4-735): Homily on the Feast of Pentecost @ Society of Archbishop Justus.