﴿ ثُمَّ إِنَّ مَرْجِعَهُمْ لَإِلَى ٱلْجَحِيمِ ﴾

“And once again: Verily, the blazing fire is their ultimate goal –”

Then indeed their return shall be to Hell-fire — this suggests that they exit from it only to drink the boiling water which is located outside it.