Tafsir of At-Tur 52:11-12

"Woe, that Day," meaning: when that occurs, or if the matter is as mentioned, then woe on that day when it occurs, "to the deniers."

"Who are in a vain discourse, amusing themselves."

Meaning: they are plunging strangely into falsehoods and lies, diverting themselves. The origin of al-khawd (plunging/wading) is walking through water; then it was used metaphorically for embarking upon anything. It became prevalent in the sense of plunging into falsehood, just as al-ihdar (presenting) is general for everything, but then its usage became predominant for being presented for torment.