The heading before the chapter summary of Mosiah 9 was written by Mormon and was part of the original record given to the Prophet Joseph Smith. Similar headings, also written by Mormon, appear at the beginning of some other books and chapters in the Book of Mormon. (The phrase “comprising chapters 9 to 22 inclusive” was added in 1879, when the Book of Mormon was published in chapter format. The word inclusive was deleted in 2013. The brief summaries that precede each chapter of the Book of Mormon were added in the 1920 edition.)
“Blessings require some effort on our part before we can obtain them, and prayer, as ‘a form of work, … is an appointed means for obtaining the highest of all blessings’ [Bible Dictionary, “Prayer”]. We press forward and persevere in the consecrated work of prayer, after we say ‘amen,’ by acting upon the things we have expressed to Heavenly Father” (David A. Bednar, “Ask in Faith,” Ensign or Liahona, May 2008, 95).