So too he placed mud upon you, that is, modesty, prudence, and consideration of your frailty. … You went, you washed, you came to the altar, you began to see what you had not seen before. This means: Through the font of the Lord and the preaching of the Lord’s passion, your eyes were then opened. You who seem to have been blind in heart began to see the light of the sacraments.

Ambrose. The Sacraments. 3.15 quoted in Thomas C. Oden & Christopher A. Hall (ed), Mark, Ancient Christian Commentary on Scripture (Intervarsity Press, 2005) 103.

Today’s Gospel according to the Roman Lectionary is Saint Mark’s account of the healing of the blind man (Mk 8: 22-26).