Doctrine & Covenants 59:8-10

“Thou shalt offer a sacrifice unto the Lord thy God in righteousness, even that of a broken heart and a contrite spirit. And that thou mayest more fully keep thyself unspotted from the world, thou shalt go to the house of prayer and offer up thy sacraments upon my holy day; for verily this is a day appointed unto you to rest from your labors, and to pay thy devotions unto the Most High.”