One of my non-Muslim friends was recently diagnosed with a very malign brain cancer. I would like him to try "habat al baraka" (nigella, black onion seed) but am not sure if this will work for cancer and for a non-Muslim. If yes, could you, please advise on how he would have to treat it?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

It is confirmed that the Prophet said: "There is healing in the black seed (scientific name: Nigella Sativa) for every disease except death." [Al-Bukhari and Muslim] It should be noted that the scholars differed in opinion with regard to the interpretation of the expression 'a healing for every disease' whether this refers to the diseases that are suitable to be treated with black seed, or to any kind of disease. So, some of them hold the first opinion while others hold the second opinion that this refers to any kind of disease without exception. So according to this view, black seed will be beneficial in treating the disease that you mentioned in the question, if Allaah so wills.

Black seed is like any other medicine, it can benefit a Muslim and a non- Muslim alike, [its benefit is not restricted to Muslims].

Besides, there are many ways of its treatment, among which is reading the Qur'an on oil and then wiping over the place of sickness with it; Ruqyah even for a non-Muslim; please refer to Fatwa: 88454. Or eating the oil with bread or drinking it by any means, or frying the seeds, or soaking them in water, eating the seeds by itself alone or with any other food. One can also mix black seed oil with honey and Zam Zam water.

Any way, we ask you to endeavour to call this man to Islam as you might be a reason of saving him from Hellfire, and this takes priority over looking for ways to treat him with black seed. Allaah says (which means): {Invite (mankind, O Muhammad ) to the Way of your Lord (i.e. Islam) with wisdom (i.e. with the Divine Inspiration and the Qur'an) and fair preaching, and argue with them in a way that is better…..}[Qur'an 16:125]. Moreover, the Prophet said: "I swear by Allaah! If Allaah guides one single man (to Islam) by your efforts, that will be better for you than possessing an abundant number of red camels (a very expensive breed of camels)." [Al-Bukhari]

So, endeavour to call this man to Islam, and that will be on the record of your good deeds on the Day of Judgement, Inshaa' Allaah.      

Allaah knows best.