﴿ فَطَافَ عَلَيْهَا طَآئِفٌۭ مِّن رَّبِّكَ وَهُمْ نَآئِمُونَ ﴾

“whereupon a visitation for thy Sustainer came upon that [garden] while they were asleep,”

Then a visitation from your Lord visited it that is a fire consumed it during the night while they slept.