|Easton's Bible Dictionary|
(1.) King of the Ammonites in the time of Saul. The inhabitants of Jabesh-Gilead having been exposed to great danger from Nahash, sent messengers to Gibeah to inform Saul of their extremity. He promptly responded to the call, and gathering together an army he marched against Nahash. "And it came to pass that they which remained were scattered, so that two of them [the Ammonites] were not left together" (1 Samuel 11:1-11).
(2.) Another king of the Ammonites of the same name is mentioned, who showed kindness to David during his wanderings (2 Samuel 10:2). On his death David sent an embassy of sympathy to Hanun, his son and successor, at Rabbah Ammon, his capital. The grievous insult which was put upon these ambassadors led to a war against the Ammonites, who, with their allies the Syrians, were completely routed in a battle fought at "the entering in of the gate," probably of Medeba (2 Samuel 10:6-14). Again Hadarezer rallied the Syrian host, which was totally destroyed by the Israelite army under Joab in a decisive battle fought at Helam (2 Samuel 10:17), near to Hamath (1 Chronicles 18:3). "So the Syrians feared to help the children of Ammon any more" (2 Samuel 10:19).
(3.) The father of Amasa, who was commander-in-chief of Abasolom's army (2 Samuel 17:25). Jesse's wife had apparently been first married to this man, to whom she bore Abigail and Zeruiah, who were thus David's sisters, but only on the mother's side (1 Chronicles 2:16).
Int. Standard Bible Encyclopedia
na'-hash (nachash, "serpent"; Naas):
(1) The father of Abigail and Zeruiah, the sisters of David (2 Samuel 17:25; compare 1 Chronicles 2:16). The text in 2 S, where this reference is made, is hopelessly corrupt; for that reason there are various explanations. The rabbis maintain that Nahash is another name for Jesse, David's father. Others think that Nahash was the name of Jesse's wife; but it is not probable that Nahash could have been the name of a woman. Others explain the passage by making Nahash the first husband of Jesse's wife, so that Abigail and Zeruiah were half-sisters to King David.
(2) A king of Ammon, who, at the very beginning of Saul's reign, attacked Jabesh-gilead so successfully, that the inhabitants sued for peace at almost any cost, for they were willing to pay tribute and serve the Ammonites (1 Samuel 11:1). The harsh king, not satisfied with tribute and slavery, demanded in addition that the right eye of every man should be put out, as "a reproach upon Israel." They were given seven days to comply with these cruel terms. Before the expiration of this time, Saul, the newly anointed king, appeared on the scene with an army which utterly routed the Ammonites (1 Samuel 11:1), and, according to Josephus, killed King Nahash (Ant., VI, v, 3).
If the Nahash of 2 Samuel 10:2 be the same as the king mentioned in 1 Samuel 11, this statement of Josephus cannot be true, for he lived till the early part of David's reign, 40 or more years later. It is, of course, possible that Nahash, the father of Hanun, was a son or grandson of the king defeated at Jabesh-gilead by Saul. There is but little agreement among commentators in regard to this matter. Some writers go so far as to claim that "all passages in which this name (Nahash) is found refer to the same individual."
(3) A resident of Rabbath-ammon, the capital of Ammon (2 Samuel 17:27). Perhaps the same as Nahash (2), which see. His son Shobi, with other trans-Jordanic chieftains, welcomed David at Mahanaim with sympathy and substantial gifts when the old king was fleeing before his rebel son Absalom. Some believe that Shobi was a brother of Hanun, king of Ammon (2 Samuel 10:1).
W. W. Davies
Nahash (9 Occurrences)
1 Samuel 11:1 Then Nahash the Ammonite came up, and encamped against Jabesh Gilead: and all the men of Jabesh said to Nahash, "Make a covenant with us, and we will serve you." (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
1 Samuel 11:2 Nahash the Ammonite said to them, "On this condition I will make it with you, that all your right eyes be put out; and I will lay it for a reproach on all Israel." (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
1 Samuel 12:12 "When you saw that Nahash the king of the children of Ammon came against you, you said to me,'No, but a king shall reign over us;' when Yahweh your God was your king. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
2 Samuel 10:2 David said, "I will show kindness to Hanun the son of Nahash, as his father showed kindness to me." So David sent by his servants to comfort him concerning his father. David's servants came into the land of the children of Ammon. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
2 Samuel 17:25 Absalom set Amasa over the army instead of Joab. Now Amasa was the son of a man, whose name was Ithra the Israelite, who went in to Abigail the daughter of Nahash, sister to Zeruiah, Joab's mother. (WEB KJV JPS ASV DBY WBS YLT NAS RSV NIV)
2 Samuel 17:27 It happened, when David was come to Mahanaim, that Shobi the son of Nahash of Rabbah of the children of Ammon, and Machir the son of Ammiel of Lodebar, and Barzillai the Gileadite of Rogelim, (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
1 Chronicles 4:12 Eshton became the father of Beth Rapha, and Paseah, and Tehinnah the father of Ir Nahash. These are the men of Recah. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
1 Chronicles 19:1 It happened after this, that Nahash the king of the children of Ammon died, and his son reigned in his place. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
1 Chronicles 19:2 David said, "I will show kindness to Hanun the son of Nahash, because his father showed kindness to me." So David sent messengers to comfort him concerning his father. David's servants came into the land of the children of Ammon to Hanun, to comfort him. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)