Abner, the son of Ner, was a prominent military leader in the Old Testament, serving as the commander of Saul's army. He was Saul's cousin, as Ner was Saul's uncle (1 Samuel 14:50-51). Abner played a significant role during the reign of King Saul and was a key figure in the power dynamics following Saul's death.

After Saul's demise, Abner supported Ish-bosheth, Saul's son, and helped him become king over Israel, while David was anointed king over Judah (2 Samuel 2:8-9). This division led to a prolonged conflict between the house of Saul and the house of David. Abner's loyalty to Ish-bosheth, however, began to waver due to a personal dispute. Ish-bosheth accused Abner of taking Saul's concubine, Rizpah, which was seen as a challenge to the king's authority (2 Samuel 3:7). Offended by the accusation, Abner decided to defect to David's side, offering to bring all Israel under David's rule (2 Samuel 3:9-10).

Abner's negotiations with David were successful, and he was warmly received by the king. However, Joab, David's military commander, harbored a grudge against Abner for killing his brother Asahel during a battle (2 Samuel 2:23). Joab deceitfully lured Abner back to Hebron and killed him in revenge (2 Samuel 3:27). David mourned Abner's death and distanced himself from the murder, declaring, "I and my kingdom are forever guiltless before the LORD concerning the blood of Abner son of Ner" (2 Samuel 3:28).

Abner's death marked a turning point in the struggle for the throne, weakening the house of Saul and paving the way for David's unification of Israel.

Amasa

Amasa, the son of Jether (also called Ithra) and Abigail, was a nephew of King David, as Abigail was David's sister (2 Samuel 17:25; 1 Chronicles 2:17). Amasa's role in the biblical narrative becomes prominent during the rebellion of Absalom, David's son.

During Absalom's revolt against David, Amasa was appointed as the commander of Absalom's army, replacing Joab, who remained loyal to David (2 Samuel 17:25). After Absalom's defeat and death, David sought to reconcile with those who had supported the rebellion. In a move to consolidate his power and perhaps to weaken Joab's influence, David offered Amasa the position of commander over his own army, replacing Joab (2 Samuel 19:13).

However, Amasa's tenure as commander was short-lived. When Sheba, a Benjamite, led a revolt against David, Amasa was tasked with assembling the men of Judah to quell the rebellion. Amasa delayed in fulfilling this duty, prompting David to send Abishai, Joab's brother, to pursue Sheba (2 Samuel 20:4-6). During the pursuit, Joab met Amasa and, under the guise of a friendly greeting, treacherously killed him (2 Samuel 20:9-10).

Amasa's death was another instance of Joab's ruthless actions to maintain his position and influence within David's kingdom. Despite David's attempts to replace Joab, Joab's power and cunning often thwarted such efforts, as seen in his dealings with both Abner and Amasa.