Charles Ellicott Commentary 2 Samuel 1:2

"it came to pass on the third day, that, behold, a man came out of the camp from Saul, with his clothes rent, and earth upon his head: and so it was, when he came to David, that he fell to the earth, and did obeisance." — 2 Samuel 1:2 (ASV)

On the third day—that is, after David’s return, not the third day after Saul’s death.

Did obeisance.—The following verses show that this was not merely an act of Eastern respect, but was intended as a recognition of David’s rank as having now become king. The messenger, although an Amalekite (2 Samuel 1:8; 2 Samuel 1:13), had earth upon his head and his clothes torn as marks of sorrow for the defeat of David’s people and the death of their king.