Anas reported that when Messenger of Allah 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 Messenger of Allah 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 ﷺ 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 ﷺ " إِنَّ الشَّيْطَانَ يَجْرِي مِنَ الإِنْسَانِ مَجْرَى الدَّمِ " .