Matthew 10

To those that the Savior called to represent Him and to preach, he taught -

"...when they deliver you up, take no thought how or what ye shall speak: for it shall be given you in that same hour what ye shall speak." (New Testament | Matthew 10:19)

We receive a little bit more incite of these words as the Savior said in modern day to thosed called to preach -

"Neither take ye thought beforehand what ye shall say; but treasure up in your minds continually the words of life, and it shall be given you in the very hour that portion that shall be meted unto every man." (Doctrine and Covenants | Section 84:85)

It becomes a little bit more clear the conditions of being given what to say. The condition is it will be given us what to say as "treasure up our minds continually the words of life". As we ponder His teachings and the scriptures, we prepare ourselves to be given what to say by the Spirit.