Tafsir Ibn Kathir (abridged)
The Evil Results of Kufr
Allah says:
وَأُحِيطَ بِثَمَرِهِ
(So his fruits were encircled), meaning his wealth, or according to the other opinion, his crops. What is meant is that what this disbeliever was afraid of and what the believer had terrified him actually had happened. A storm struck his garden, a garden which he had erroneously thought would last forever, distracting him from thoughts of Allah, may He be glorified.
فَأَصْبَحَ يُقَلِّبُ كَفَّيْهِ عَلَى مَآ أَنْفَقَ فِيهَا
(And he began Yuqallibu his hands over what he had spent upon it,) Qatadah said: "He was clasping his hands together in a gesture of regret and grief for the wealth he had lost."
Continue reading the tafsir of ayahs 42–44