It is implied in this verse that Jeremiah received this Word from the Lord while he was in captivity. Jeremiah received a Word of hope and promise from God, along with a clear warning of the wickedness of the time. Regardless of the circumstances you are facing, there is hope for you in the Word of God. Even after reading the Bible through a hundred times, go to Him for a new Word and let Him fill you with hope.
During his prayer, Jeremiah was told by the Lord that there was hope following the destruction of Jerusalem and the dispersion of His people as a result of their sins. He promised Jeremiah that if His people simply prayed to Him, He would do great and mighty things for them.
God has promised to restore Israel to their land. It has been promised that their property will be restored and that their nation will again be populated with joyful men and singing women. It has been promised that He would send a descendent of David to be their Messiah and that He would be called The Lord My Righteousness.

Dear Heavenly Father, it is encouraging to know that faithful men of God, such as Jeremiah, endured hardships in order to endow us with the holy Scriptures that guide us in the way of truth. Thank You for being a merciful and faithful God. My Lord, thank You for keeping all Your promises to Israel and the Church. Thank you for listening to Your people's cries and calls. I am deeply grateful to You for the many precious promises you have made that will never fail because Your Word is always true and trustworthy. 
In Jesus's name I pray. Amen.