كتاب السلام
39
The Book of Greetings
(9)
Chapter: 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
(9)
باب بَيَانِ أَنَّهُ يُسْتَحَبُّ لِمَنْ رُئِيَ خَالِيًا بِامْرَأَةٍ وَكَانَتْ زَوْجَةً أَوْ مَحْرَمًا لَهُ

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:

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.
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 ‏"‏ ‏.‏
Reference : Sahih Muslim 2174
In-book reference : Book 39, Hadith 32
USC-MSA web (English) reference : Book 26, Hadith 5404
  (deprecated numbering scheme)