When David heard that Absalom was slain

The Tomb of Absalom still stands at the foot of the Mount of Olives to this day. This song is sung by BYU students.
When David heard that Absalom was slain,
he went up into his chamber over the gate and wept,
and thus he said; My son, my son, O Absalom my son,
would God I had died for thee!

[@dissimulo1868]

2 Samuel Chapter 18: Then
Joab said, “I cannot linger with you.” And he took three spears in his
hand and thrust them through Absalom’s heart, while he was still alive in the midst of the terebinth tree.
15 And ten young men who bore Joab’s armor surrounded Absalom, and struck and killed him. 16 So Joab blew the trumpet, and the people returned from pursuing Israel. For Joab held back the people. 17 And
they took Absalom and cast him into a large pit in the woods, and laid a
very large heap of stones over him. Then all Israel fled, everyone to
his tent. 18 Now Absalom in his lifetime had taken and set up a pillar for himself, which is
in the King’s Valley. For he said, “I have no son to keep my name in
remembrance.” He called the pillar after his own name. And to this day
it is called Absalom’s Monument.
So this is not actually Absalom's Tomb....