"They will circle between it and a boiling hot fluid," meaning: the hot [water] whose heat has reached its peak.
Muhammad said: "Anna ya'ni wa huwa anin" (it boils, it is boiling, and it is a boiling thing).
﴿يَطُوفُونَ بَيْنَهَا وَبَيْنَ حَمِيمٍ آنٍ﴾ يَعْنِي: الْحَار الَّذِي انْتهى حَرُه.
قَالَ محمدٌ: أَنى يأني وَهُوَ آنٍ.
