During the reign of David, there was a famine for three successive years; so David sought the face of the Lord.
Avenging the Gibeonites in 2nd Samuel 21, God reminded David that Saul broke Israel's promise to the Gibeonites. Some may not have noticed Saul's actions, but Got did. Once David made things right with the Gibeonites, God's blessing returned upon the land. God doesn't take making promises lightly.
Never make a promise you can't keep; always keep a promise that you make. All you need to say is simply "Yes" or "No"; anything beyond this comes from the evil one (Matthew 5:37); Above all, my brothers and sisters, do not swear - not by heaven or by earth or by anything else. All you need to say is a simple "yes" or "no." Otherwise you will be condemned (James 5:12).
Your servant in Christ, Hank