Andrew Bonar offers heartfelt comfort to his sister-in-law, Mrs. Grant, in her time of grief following the death of her husband, the Rev. Wm. Grant. He acknowledges the deep bitterness of her heart and emphasizes that true comfort can only come from the Lord. Bonar encourages her to view her suffering as a means to draw closer to Jesus, reminding her that even in sorrow, there is a purpose that leads to spiritual growth and reliance on Christ's righteousness. He urges her to seek solace in the blood and obedience of Jesus, who understands her pain and offers consolation.