John Gill Commentary 2 Samuel 13:36

"And it came to pass, as soon as he had made an end of speaking, that, behold, the king`s sons came, and lifted up their voice, and wept: and the king also and all his servants wept very sore." — 2 Samuel 13:36 (ASV)

And it came to pass, as soon as he had made an end of
speaking
As soon as the above words were out of his mouth:

that, behold, the king's sons came :
into the palace, and into the apartment where the king was:

and lifted up their voice and wept ;
not being able to tell the sorrowful news with their mouths, but declared it by gestures:

and the king also and all his servants wept very sore ;
they joined the king's sons in weeping, and were the more moved to it by their weeping, and the rather, since hereby the news of Amnon's murder was confirmed.