II. The Lord’s Day

From The Catechism of the Catholic Church

2181
The Sunday Eucharist is the foundation and confirmation of all Christian
practice. For this reason the faithful are obliged to participate in the
Eucharist on days of obligation, unless excused for a serious reason (for
example, illness, the care of infants) or dispensed by their own
pastor.¹¹⁹ Those who deliberately fail in this obligation commit a
grave sin.

PART THREE: LIFE IN CHRIST

SECTION TWO THE TEN COMMANDMENTS
- CHAPTER ONE YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND
  - Article 3 THE THIRD COMMANDMENT
    - II. The Lord’s Day

From The Catechism of the Catholic Church – rosary.team