It is narrated from Sayyiduna Abu Khuzamah (may Allah be pleased with him), he says: I said, "O Messenger of Allah! These treatments we use through medicine, incantations, and preventive measures, what is your opinion about them? Do they repel anything from Allah Almighty's decree?" The Prophet (peace and blessings be upon him) said: "These things are also from Allah Almighty's decree."

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that one day he was riding behind the Messenger of Allah (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) said to him: "O boy! I am going to teach you some words; Allah Almighty will benefit you through them. Guard (the commandments of) Allah, He will guard you. Guard (the commandments of) Allah, you will find Him before you. Whenever you ask, ask from Allah, and whenever you seek help, seek help from Allah. And know that if the entire Ummah were to gather together to benefit you with something, they would not be able to benefit you except with that which Allah has written for you. Similarly, if the entire Ummah were to gather together to harm you with something, they would not be able to harm you except with that which Allah has written against you. The pens have been lifted and the pages have dried."

(Second chain) There is a similar narration, but with the addition of these words: "So recognize Allah in times of ease, He will recognize you in times of hardship. Thus, if all of creation intends to benefit you with something that Allah has not written for you, (no matter what they do) they will not be able to do so. Similarly, if they resolve to harm you with something that Allah has not decreed for you, they will not have the power to do so either. So know that there is great good in being patient over disliked matters, and help comes with patience, relief comes with hardship, and ease comes with difficulty."