Key points from this section:

• Prayer in Liberty Jail: This section contains a heartfelt prayer and prophecy written by Joseph Smith while he was imprisoned in Liberty Jail, expressing his anguish and pleading for the Lord’s help for the suffering Saints.

• Peace and Promises: The Lord responds with words of comfort, assuring Joseph that his afflictions will be temporary and promising exaltation and triumph over his enemies if he endures faithfully.

• Principles of Priesthood: The revelation outlines the principles by which the priesthood should be exercised, emphasizing persuasion, long-suffering, gentleness, meekness, love unfeigned, and pure knowledge."

Read this chapter for free at https://byustudies.byu.edu/online-book/doctrine-and-covenants-contexts/section-121.