Abbaan Ibn Uthmaan narrates from his father that the Prophet Sallallahu Alaihi Wasallam said : “Nothing can harm a person who recites three times every morning and evening : Bismillahil lazi Laa yadhurru ma’a ismihi shay’un fil ardhi wa laa fis samaa’i Wa huwas sami’ul aleem. (Meaning : In the Name of Allah, nothing in the earth or heavens can be harmed when His name is taken. He is all-hearing and all-knowing). Now, Abbaan himself had been afflicted with a form of paralysis. A man (realizing that he was partially paralyzed) began staring at him. Abaan said to him : “Why do you stare at me? The hadith is as true as I have narrated it, except that I did not recite it one day and Allah had passed His decree upon me.” (Tirmidhi, Abu Dawood)
Khalid ibn Walid Radhi Allahu Anhu, the Muslim commander, laid siege to Hira. Upon invitation an old man by the name of Abdul Masih ibn Hayyaan ibn Baqila came out to speak to the Muslims. In his hand he had a poison. Khalid asked him : “What do you have in your hand?”
The old man replied : “This is poison. If you agree to what I have to say, then well and good. If you do not, I will drink this poison so that I do not have to return to my people with such conditions which they dislike.”
Khalid took the poison from the old man’s hand and recited the following : “In the Name of Allah, nothing in the earth or heavens can be harmed when His name in taken.” He then swallowed the poison.
The old man returned to his people saying : “I return to you from such people who are not harmed by poison.” (Abu Yusuf, Kitabul Kharaj, p.143)
The Sahabah had firm conviction in the words of Allah’s Rasool Sallallahu Alaihi Wasallam. They knew that success and safety were in the teachings of
their leader and master, Nabi Sallallahu Alaihi Wasallam.