Let us rejoice.
On this Sunday, from the very first word of the introit, the Church invites us to rejoice. Is that so astonishing? Sunday is quintessentially a day of joy. After a week of work, man is invited by God Himself to rest. Such is the commandment, or more exactly the word, a word of love, which God addressed on Mount Sinai to the people He had just brought out of Egypt:
"Six days shalt thou labour, and shalt do all thy works. But on the seventh day is the Sabbath of the Lord thy God: thou shalt do no work on it, thou nor thy son, nor thy daughter, nor thy manservant, nor thy maidservant, nor thy beast, nor the stranger that is within thy gates. For in six days the Lord made heaven and earth, and the sea, and all things that are in them, and rested on the seventh day: therefore the Lord blessed the seventh day, and sanctified it." (Ex 20:9-11)
God had just set His people free from Pharaoh, and He did not want greed for lucre to shackle it, and lead it through a ceaseless frenzy of work to forget its Maker. The seventh day therefore became the day on which man would remember that he had been freely liberated by God from bondage.
For Christians, Sunday has been enriched with a new gift. Man, who from the very beginning had rebelled against God, had to be liberated from another form of bondage, a deeper, more universal, and multifaceted one, that is, sin. Man needed to be reconciled with God, with the design God had prepared in His immense love for His so puny creature: eternal beatitude, that is to say, life in communion with God, the vision of God for eternity. Such is the reward of rewards, to which God in His goodness calls us.