The Introit refers to Sion, holy mount of Jerusalem, so often mentioned as the symbol of the interior life of the faithful soul. It speaks also of the soul as a docile sheep led by God. It publishes His coming "to save the nations." After calling upon God to "stir up our hearts" in the Prayer so as to "prepare," notice how the Epistle stresses social charity, "to receive one another as Christ also hath received you."
Again, the Gospel enumerates some of the interior and social "works of Christ," which, together with His miracles, testify that He is the long-expected Divine Saviour of the world. The blind of soul now see. The lame of will now walk. The lepers of sin are absolved. The poor become rich with a new Gospel.
A true bishop who vigorously opposed heretics, and even criticized the Emperor Theodosius for his heretical views, St. Ambrose is widely recognized as the person who converted St. Augustine. Highly learned, and a magnificent orator, this famed Doctor of the Church, contributed much to doctrine but was also highly skilled in music and is widely regarded as the originator of the Ambrosian Rite, which liturgy is still used in Milan, his see. His glorious feast is celebrated December 7. Under the 1962 rubrics, his feast is not commemorated in this Sunday's Mass.
Deo grátias!