What was the wisdom behind the Prophet Muhammad (saw) cautioning the two Ansari men when they greeted him and his wife at the mosque gate?
 Narrated `Ali bin Al-Husain:                     Safiya, the wife of the Prophet told me that she went to Allah's Apostle to visit him in the mosque while he was in I`tikaf in the last ten days of Ramadan. She had a talk with him for a while, then she got up in order to return home. The Prophet accompanied her. When they reached the gate of the mosque, opposite the door of Um-Salama, two Ansari men were passing by and they greeted Allah's Apostle . He told them: Do not run away! And said, "She is (my wife) Safiya bint Huyai." Both of them said, "Subhan Allah, (How dare we think of any evil) O Allah's Apostle!" And they felt it. The Prophet said (to them), "Satan reaches everywhere in the human body as blood reaches in it, (everywhere in one's body). I was afraid lest Satan might insert an evil thought in your minds."