The most solemn oath the Lord could make was by his own name (see also Genesis 22:16; Jeremiah 51:14; compare Amos 4:2; Psalm 110:4; Hebrews 6:13–14).
Jacob's pride (see study note on Amos 8:7): Jacob can mean "cheat" (Genesis 27:36), while Israel means "he struggles with God" (Genesis 32:28). Amos uses Jacob to show the stubborn arrogance that often characterized the people of Israel.