Albert Barnes' Notes on the Whole Bible - 2 Samuel 18:19
Ahimaaz was a well-known runner 2 Samuel 18:27. Speed was a heroic virtue in those simple times (compare 2 Samuel 2:18). In Hezekiah’s reign 2 Chronicles 30:6, 2 Chronicles 30:10 we find an establishment of running post-men; and the same name (“runners”) is given Esther 3:13 to the Persian posts, though at that time they rode on mules and camels.Bear tidings - The original word is used almost exclusively of bearing good tidings, and hence, is rendered in the Septuagint (though not always)... read more
The Pulpit Commentary - 2 Samuel 18:31
Tidings, etc. The literal meaning is more fit for the mouth of a slave. "Let my lord the king learn the tidings that Jehovah hath judged (and delivered) thee this day from the hand," etc; that is, God, sitting as Judge at the assize of battle; hath given sentence for thee, and pronounced thy acquittal. The same phrase occurs in 2 Samuel 18:19 . read more