John Gill Commentary 2 Samuel 19:4

"And the king covered his face, and the king cried with a loud voice, O my son Absalom, O Absalom, my son, my son!" — 2 Samuel 19:4 (ASV)

But the king covered his face
And would not see his generals, and thank them for their services: but wrapped himself in his mantle, after the manner of mourners:

and the king cried with a loud voice, O my son Absalom! O Absalom, my
son, my son !
and this was some time, perhaps some days after he had received the news of his death, since Joab and the army were returned from the battle; had it been a sudden start of passion, upon first hearing thee news, and had continued a few hours, it would have been more excusable;

But to continue some days, as it is very probable it did, was very unbecoming.