Ahimaaz in Fausset's Bible Dictionary

("brother of anger", i.e. "choleric".) 1. 1 Samuel 14:50. 2. Zadok the priest's son; the messenger in Absalom's rebellion, with Jonathan, Abiathar's son, to carry tidings from Hushai, David's friend and spy. Zadok and Abiathar, who took back the ark to the city at David's request, were to tell them while staying outside the city at Enrogel whatever Hushai directed. They told David the counsel of Ahlthophel for an immediate attack, which David should baffle by crossing Jordan at once. They narrowly escaped Absalom's servants at Bahurim, the woman of the house hiding them in a well's mouth, over which she spread a covering with ground grain on it, and telling the servants what was true in word, though misleading them: "they be gone over the brook of water." Bahurim, the scene of Shimei's cursing of David, was thus made the scene of David's preservation by God, who heard his prayer (1 Samuel 16:12; Psalm 109:28). David's estimate of Ahimaaz appears in his remark on his approach after the battle (2 Samuel 18:27): "he is a good man, and cometh with good tidings." Though Cushi was later in arriving he announced the fate of Absalom, which Ahimaaz with courtier-like equivocation evaded announcing, lest he should alloy his good news with what would be so distressing to David. Joab, knowing David's fondness for Absalom, had not wished Ahimaaz to go at all on that day, but youths will hardly believe their elders wiser than themselves. Good running was a quality much valued in those days, and Ahimaaz was famous for it. The battle was fought on the mount of Ephraim W. of Jordan, and Ahimaaz ran by the plain of the Jordan to David at Mahanaim. Compare as to Asahel 2 Samuel 2:18; Elijah, 1 Kings 18:46. Compare as to runners before kings 2 Samuel 15:1; 1 Kings 1:5; as to courier posts, 2 Chronicles 30:6; 2 Chronicles 30:10; Esther 3:13; Esther 3:15; Esther 8:14. Comparing 1 Kings 4:2 with 1 Chronicles 6:10, some infer that Ahimaaz died before he attained the priesthood, and before his father Zadok, who was succeeded by Ahimaaz's son, Azariah. (See ABIATHAR) 3. 1 Kings 5:7; 1 Kings 5:15.

Link: https://bible-history.com/faussets/A/Ahimaaz/