Commands, wishes, and other requests may also assign an action to an associated rather than proper bearer. The source discusses such forms with spring, daytime, and effort.
فَلْيُنْبِتِ الرَّبِيعُ مَا شَاءَ
Let spring cause whatever growth it will.
وَلْيَصُمْ نَهَارُهُ
Let his day fast.
وَلْيَجِدَّ جِدُّكَ
Let your effort strive earnestly.
The expressions retain nondeclarative force, yet spring is a time, daytime a setting, and effort an abstraction. Their action relations can still be figurative.