33 And after Easter's Holy Day of salvation, you shall come on each successive day, beginning from the second day of the week, after the assembly into the Holy Place of the Resurrection, and there, if God permit, you shall hear other Lectures; in which you shall again be taught the reasons of every thing which has been done, and shall receive the proofs thereof from the Old and New Testaments,— first, of the things done just before Baptism,— next, how you were cleansed from your sins by the Lord, by the washing of water with the word —and how like Priests you have become partakers of the Name of Christ—and how the Seal of the fellowship of the Holy Ghost was given to you—and concerning the mysteries at the Altar of the New Testament, which have taken their beginning from this place, both what the Divine Scriptures have delivered to us, and what is the power of these mysteries, and how ye must approach them, and when and how receive them—and at the end of all, how for the time to come ye must behave yourselves worthily of this grace both in words and deeds, that you may all be enabled to enjoy the life everlasting. And these things shall be spoken, if it be God's pleasure.
Source: Catechetical Lectures (New Advent)