Geba was situated between Jonathan’s forces at Gibeah and Saul’s forces at Michmash. A deep gorge (a steep, narrow valley) separated Geba and Michmash (see 1 Samuel 13:23; 14:5).
The ram’s horn (shofar in Hebrew) was used to send signals, such as gathering an army (Judges 3:27). For other uses, see Leviticus 25:9; 2 Samuel 6:15; 15:10; 18:16; 20:1; Hosea 5:8; Joel 2:15.
Non-Israelites often used the term Hebrews in a disrespectful way (see 1 Samuel 14:11; 29:3; see also Genesis 39:14; 43:32). Saul might have used it to bring pride to their identity.