Is it permissible to purchase information from someone in exchange for money, such that the money is paid first, and then I am informed of the information?

This transaction can be rectified as a lease (ijara) for the service of teaching a permissible herbal mixture, similar to online medical consultations where a doctor expends his knowledge and expertise in exchange for a fee. Ibn Hazm permitted leasing for teaching the Quran, knowledge, and ruqyah, citing the absence of any text prohibiting it, and indeed, there are texts that permit it.