Doctrine & Covenants 29-35
"Open your mouth"
D&C 28:16 - "Thou must open thy mouth at all times, declaring my gospel with the sound of rejoicing."
D&C 29:7 - "Mine elect hear my voice and harden not their hearts."
D&C 30:1 - "You have feared man and have not relied on me for strength as you ought."
D&C 31:3 - "Declare glad tidings of great joy."
D&C 32:3 - "I myself will go with them and be in their midst."
D&C 33:8, 9, 10 - "Open your mouths."
D&C 34:10 - "Lift up your voice."
D&C 35:4 - "Thou shalt do great things."
I'm seeing a theme here - open your mouth and share the gospel. Elder Perry gave a great talk on this last week at general conference. Here are his suggestions for what to say when we open our mouth:
What would each of us say if we had to open our mouth three times? If I may, I would like to offer a suggestion. First and foremost, we should declare our belief in Jesus Christ and His Atonement. His redeeming act blesses all mankind with the gift of immortality and the potential of enjoying God's greatest gift to man, the gift of eternal life.
The second time we open our mouths, we should tell in our own words the story of the First Vision—that is, our knowledge of a boy not quite 15 years of age who went into a grove of trees and, after sincere and humble prayer, he had the heavens open to him. After centuries of confusion, the true nature of the Godhead and God's true teachings were revealed to the world.
The third time we open our mouths, let us testify of the Book of Mormon: Another Testament of Jesus Christ. The Book of Mormon complements the Bible in giving us a greater understanding of the doctrines of our Savior's gospel. The Book of Mormon is the convincing evidence that Joseph Smith is truly a prophet of God. If the Book of Mormon is true, there was a restoration of the priesthood. If the Book of Mormon is true, then with the power of that priesthood, Joseph Smith restored the Church of Jesus Christ.