"Those who are in vain discourse playing." Their vain discourse is their denial.
Muhammad said: "Woe" (al-wayl) is a word the Arabs use regarding anyone who has fallen into destruction.
﴿الَّذِينَ هُمْ فِي خَوْضٍ يَلْعَبُونَ﴾ وخوضهم التَّكْذِيب.
قَالَ محمدٌ: (الويلُ) كلمةٌ تَقُولهَا الْعَرَب فِي كل من وَقع فِي هلكة.