Sahih Muslim 2174
Sahih Muslim · Book 39: The Book of Greetings · It Is Recommended For The One Who Is Seen Alone With A Woman Who Is His Wife Or Mahram, To Say; "This Is So-And-So,' To Ward off Suspicion
Anas reported that when Allah's Messenger (ﷺ) was in the company of one of his wives a person happened to pass by them. He called him and when he came, he said to him:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ بْنِ قَعْنَبٍ ، حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ ، عَنْ ثَابِتٍ الْبُنَانِيِّ ، عَنْ أَنَسٍ ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ مَعَ إِحْدَى نِسَائِهِ فَمَرَّ بِهِ رَجُلٌ فَدَعَاهُ فَجَاءَ فَقَالَ " يَا فُلاَنُ هَذِهِ زَوْجَتِي فُلاَنَةُ " . فَقَالَ يَا رَسُولَ اللَّهِ مَنْ كُنْتُ أَظُنُّ بِهِ فَلَمْ أَكُنْ أَظُنُّ بِكَ . فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ الشَّيْطَانَ يَجْرِي مِنَ الإِنْسَانِ مَجْرَى الدَّمِ " .
0 so and so, she was my such and such wife. Thereupon he said, Allah's Messenger, if I were to doubt at all, I would have entertained no doubt about you at least. Thereupon Allah's Messenger (ﷺ) said: Verily Satan circulates in the body like blood.