Will the author of scientific books sold in foreign markets be rewarded for beneficial knowledge?

If the books being traded are beneficial to people in their religious or worldly affairs, and the reward is sought for them, then it is hoped that the reward will be attained. Their benefit may also continue after death as knowledge from which benefit is derived, as stated in the Hadith: "When a person dies, all his deeds come to an end except for three: ongoing charity, knowledge from which benefit is derived, or a righteous child who prays for him." The beneficial knowledge includes all permissible knowledge that benefits a person, whether it is religious or worldly, but religious knowledge is at the forefront. The knowledge from which benefit is derived refers to otherworldly knowledge that benefits one's religion, whether through teaching, dissemination, or authoring beneficial books, even if it is for a fee, provided there is a pure intention.