Sahih Muslim
The Book on Salutations and Greetings (Kitab As-Salam)
Book Number: 026 / Hadith Number: 5405
Safiyya daughter of Huyyay (the wife of Allah's Apostle) reported that while Allah's Messenger (may peace be. upon him) had been observing I'tikaf, I came to visit him one night and talked with him for some time. Then I stood up to go back and he (Allah's Apostle) also stood up with me in order to bid me good-bye. She was at that time residing in the house of Usama b. Zaid. The two persons from the Ansar happened to pass by him. When they saw Allah's Apostle (may peace be upon him). they began to walk swiftly, thereupon Allah's Messenger (may peace be upon him) said to them: Walk calmy, she is Safiyya daughter of Huyyay... Both of them said: Messenger, hallowed be Allah, (we cannot conceive of ab., ug doubtful even in the remotest corners of our minds), whereupon he said: Satan circulates in the body of man like the circulation of blood and I was afraid lest it should instill any evil in your heart or anything. This hadith has been reported on the authority of Safiyya, the wife of Allah's Apostle (may peace be upon him), through another chain of transmitters (and the words) are:" She went to Allah's Apostle (may peace be upon him) to visit him as he was observing I'tikaf in the mosque during Ramadan. She talked with him for some time and then stood up to go back and Allikh's Apostle (may peace be upon him) stood up in order to bid her good-bye." The rest of the hadith is the same except with the variation of the words that Allah's Apostle (may peace be upon him) said:" Satan penetrates in man like the penetration of blood (in every part of body)."