首楞嚴義疏注經 8.464

8.464

即前婬習為因也。色能動亂身心，如風鼓物，報招鬼質，還復託風。風質元虛，因習所致。因果相對，豈徒然哉！

This is the previous habit of lust as the cause. Sex can agitate body and mind like wind stirring objects; the retribution incurred is the body of a ghost, which again attaches to the wind. The substance of wind is fundamentally void, yet caused by habitual tendencies. When cause and effect correspond, how could it be in vain!