Chapter 57: The Book of Commentary on the Qur'an
Abdullah b. Mas' ud said in connection with the verse: " Those whom they call upon, themselves seek the means of access to their Lord," that that verse was revealed in connection with a party of Arabs who used to worship a group amnogst the jinn; the jinn embraced Islam but the people kept worshipping them without being conscious of it. Then this verse was revealed: " Those whom they call upon, themselves seek the means of access to their Lord."
Sahih Muslim 3030d