Answered by Shaykh Abdul-Karim Yahya, SunniPath Academy Teacher
Is it permissible to accept or demand a payment for writing or performing (blowing in to water etc.) a ruqyah (Ta’weez, Amulet, etc.) ?
In The Name of Allah, Most Merciful and Compassionate
It is permissible to hire someone or pay them a fee for performing a ruqya, writing an amulet, and similar services with a foundation in Sacred Law and it is permissible for them to accept this payment. However the task they perform must entail an amount of difficulty that usually requires payment.
One of the proofs the jurists used for the validity of paying a fee for a task (ja’ala) are the prophetic traditions related by Bukhari, Muslim, and others in which Abu Sa’id, Allah be pleased with him, performed a ruqya for the fee of 30 goats (and or sheep). Shaykh Ibn Hajar al-Haytami (Allah have mercy on him) said concerning these prophetic traditions: “From them al-Bilqini derived (and al-Zarkashi followed him) its [a fee’s] permissibility for that which the infirmed is helped by of medicine or ruqya”. Ibn Qasim (Allah’s mercy be upon him) added in his super commentary on Tuhfa: “With the condition that there is some effort in this.”
If the contract consists of hiring their services (ijara), then the service must have a value. So it is not valid to hire someone to say a phrase that requires no effort, but it is valid if the service does entail some difficulty. Ali Shabramallasi (Allah have mercy on him) said: “The validity of hiring to undo witchcraft is taken from this because the one who performs this endures the difficulty of writing and the like.” And Allah knows best and He alone gives success (tawfiq).
 See: Ibn Hajar al-Haytami, Hawashi al-Sharwani Wa Ibn Qasim al-Abbadi ‘Ala Tuhfah al-Muhtaj Bisharh al-Minhaj (Beruit, Dar Ihya’ al-Turath al-‘Arabi), 6:363.
 See Minhaj: Yahya Bin Sharaf al-Nawawi, Minhaj al-Talibin Wa ‘Umdah al-Muftin (Eygpt: Sharikah Maktabah wa Matba’ah Mustafa al-Babi al-Halabi wa Awladuhu, 1338 A.H. [1920 C.E.]), p.76.
 See Shibramalisi’s super commentary on Nihaya: Muhammad Ramli, Nihayah al-Muhtaj ila Sharh al-Minhaj (Beruit, Dar Ihya’ al-Turath al-‘Arabi), 5:270.