Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
There is no authentic evidence for the supplications you have mentioned. However, you can recite any part of the Qur’an as a therapy and ruqyah.
With regard to your question, late Sheikh Muhammad `Ali Al-Hanooti, a former member of the Fiqh Council of North America, stated,
We don’t have any authentic narrations for any of those purposes, but we believe that any recitation of Quran could help with cure and therapy. This is based on what was narrated in Sahih Al-Bukhari that a man was bitten by a snake when the Companions of the Prophet were on a trip. The man asked them to recite Qur’an over the wound for cure, and it worked.
The Prophet (peace and blessings be upon him) used to say supplications for what is known as ruqyah (protective supplications). You can make any duaa for any patient as well as you can recite Qur’an over him. Everything of that would do and be of help.
Sheikh Hamed Al-`Ali, instructor of Islamic Culture at the Faculty of Education, Kuwait and Imam of Dahiat As-Sabahiyya Mosque, adds,
There is no specific evidence that mentions a particular merit of reciting Surat Al-Muzaammil for the patient in order to seek recovery. However, the whole Qur’an is a cure for all diseases.
As for the second part of the question, here are some suggestions for seeking recovery for a sick child:
1- The best you can do when your child is sick is to place your hand on the child’s head and recite Surat Al-Fatihah seven times and blow with a little bit from your saliva on the child after each recitation.
2- Recite the two protective Surahs, Al-Falaq and An-Nas (Chapters 113 and 114), each one three times.
Also, you can say the following du`aa’:
Allahumma rabba an-nas adhhibi al-ba’sa, ishfi anta ash-shafi la shifa’a illa shifa’uka, shifa’an la yughadiru saqaman
(O Allah, O Lord of Mankind, remove the affliction and send down cure and healing, for no one can cure but You; so cure in such a way that no trace of illness is left).
Allah Almighty knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.