All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The origin of the Arabic word Wayl means destruction and punishment and some scholars like Sa’eed ibn Al-Musayyab, stated that it means a valley in Hellfire, which is actually a kind of destruction and punishment.
However, we have not come across any scholar who said that it means a river in Hellfire. Nonetheless, ‘Abdullaah ibn Mas’ood interpreted the saying of Allaah (which means): {So they are going to meet evil.}[Quran 19:59] to mean a river in Hellfire.
Allaah Knows best.