Father Smith returned home from his spring 1829 visit to Joseph with a revelation in hand saying he was called to the marvelous work. Joseph’s younger brother Samuel returned home a few weeks later having been baptized and “greatly glorifying and praising God, being filled with the Holy Spirit.” Joseph’s older brother Hyrum wanted to get in on the action. He went to Joseph’s place in Pennsylvania and asked what the Lord had in store for him. “Wait,” the Lord replied.
Section 11 includes all of the anticipation of section 4 and later revelations, and it commands Hyrum to take part. There is a restraining tone to this one, however, that is not in the others. Note the several specific commands from the Lord to Hyrum: say nothing but repentance, keep commandments, assist with the marvelous work. The Lord makes these the conditions on which he will grant Hyrum’s desires. As with so many others, the entire revelation follows this conditional formula. Hyrum has a spiritual gift to know whatever he righteously desires by faith and the power of the Holy Ghost. The Lord tells him to trust it and promises to enlighten his mind and fill him with joy.
Unlike his father, Hyrum is not yet called to preach but rather to wait until he has the Book of Mormon and the restored Church. Then, as Hyrum desires, he will be a successful preacher of the gospel. For now he should keep the Lord’s commandments, be patient, appeal to the Spirit, and cleave unto Christ wholeheartedly in order to assist with the printing of the Book of Mormon. “Be patient until you shall accomplish it” (D&C 11:19), the Savior tells him. That is his work for now, simply to keep the commandments as best he can. He is not to declare the Lord’s word but to obtain it. Then his tongue will be loosed, and then, if he desires, he will be full of the Spirit and the Lord’s word, the power of God to convince many. So for now Hyrum should not preach but study the scriptures.
This revelation channels Hyrum’s zeal. He is like a wild horse. Here the Lord bridles him, careful not to break his spirit but to train him. This revelation gives Hyrum, and so many others since him, the formula for becoming successful preachers of the gospel. Having the Lord’s conditional promise of power to convince by the Spirit if he will first learn the gospel, Hyrum spent a year searching the scriptures and helping with the publication of the Book of Mormon. When the Lord spoke to him again in April 1830, the Book of Mormon was printed, the Church was restored, the marvelous work had come forth, and Hyrum had the knowledge to pair with his desire to declare the good news. Having been promised in May 1829 that the Lord would loose his tongue if he would obtain the word, Hyrum learned in April 1830 that “thy heart is opened, thy tongue loosed; and thy calling is to exhortation” (D&C 23:3).
 “History, 1838–1856, volume A-1 [23 December 1805–30 August 1834],” p. 19, The Joseph Smith Papers, accessed July 22, 2020.
From Doctrine and Covenants Minute
The 1833 Book of Commandments gives the date of the revelation recorded in section 11 as May 1829, though it was most likely received after May 15, when John the Baptist restored the Aaronic priesthood to Joseph and Oliver Cowdery. Not long after this event, Joseph’s younger brother Samuel visited Joseph and Oliver. Joseph later wrote in his history, “On the twenty-fifth day of that same month [May] in where we had been baptized and ordained; Oliver Cowdery baptized him [Samuel Smith], and he returned to his father’s house greatly glorifying and praising God, being filled with the Holy Spirit.” Samuel apparently shared his witness with Joseph’s oldest living brother, Hyrum, for in the spring of 1829 Hyrum, visited Joseph in Harmony, Pennsylvania. Joseph records, “Not many days afterwards, my brother Hyrum Smith came to enquire concerning these things, when at his earnest request, I enquired of the Lord through the Urim and Thummin, and received for him the following” (History, 1838–1856, vol. A-1, p. 19, JSP).
If Samuel was baptized on May 25, and Joseph and Oliver left Harmony to move to Fayette, New York, on May 29, it leaves only a tight window for Hyrum to speak with Samuel and then travel to Harmony. Because of this time frame, it is best to assume that the dates in Joseph’s history are not exact but are approximations in a history written almost a decade later or are possible insertions by scribes assisting in the writing of the history.
See Historical Introduction, “Revelation, May 1829–A [D&C 11],” p. 28, The Joseph Smith Papers, accessed October 2, 2020, https://www.josephsmithpapers.org/paper-summary/revelation-may-1829-a-dc-11/1