Rashi: This is Midah k'Neged Midah. They widened the Nefesh to swallow much food and drink, and opened their mouths wide - so the grave will do to swallow them.

Radak: This is a metaphor for the many Yisraelim who will die. The grave widens to swallow the dead. (Refer to 5:14:4:4.)

Rashi: It opened [Metzudas Tziyon - wide].

Rashi: It is without end - because they had no end to their pampering themselves.

Malbim: It is one who did not put a limit to his desire - therefore the grave will not limit its desire to swallow people.

Rashi: That of Yerushalayim.

Radak: That of Eretz Yisrael. The loss of beauty was the honored people and the multitudes who descended to the grave.

Malbim: When a city ceases, first the great voice of Simchah ceases, and after the usual tumult, and afterwards its beauty - the king and officers. Here, it reverses the order, for the city will cease suddenly, as if the grave opened its mouth and swallowed the entire city suddenly; all ceased at once.

Radak: This is the multitude mentioned.

Rashi: The merry people in it. Radak - they delighted over their great good - also they descended to the grave.

Radak citing Targum Yonasan: The strong ones in [the city].

Radak: The enemy rejoiced over it.

Malbim: It is as if amidst their inebriety and reveling they will fall to the grave, and not sense [their fall]. They will revel also in the grave; "Bah" refers to "She'ol".