1)
Why does it say "Lachen"?
1.
Malbim: The punishment will be for using the Kelim of Beis Hashem (refer to 51:51:2:1), like Daniel explained.
2)
What is "Ye'enok Chalal"?
1.
Rashi: One will scream 'Chalal'.
2.
Radak: At the time of death, the Neshamah lets out Anakah and screaming.
