Now the three sons of Zeruiah were there, Joab and Abishai and Asahel, and Asahel was as swift of foot as one of the gazelles in the field. Bible

“three sons of Zeruiah were there.” Zeruiah was David’s sister (1 Chron. 2:13-16), so Joab, Abishai, and Asahel were David’s nephews.

“as swift of foot as one of the gazelles.” Asahel was a fast, smooth runner who could run long distances. People like that were valuable in the ancient world, which had not telephone or other quick method of long-distance communication. They often became royal runners.

Commentary for: 2 Samuel 2:18