What he said before the man came in, and after
Aisha asked him about the difference.
The words
بِئْسَ أَخُو الْعَشِيرَةِ، وَبِئْسَ ابْنُ الْعَشِيرَةِ
Biʾsa akhu-l-ʿashīrah, wa biʾsa-bnu-l-ʿashīrah
What an evil brother of his clan, and what an evil son of his clan.
Where this comes from
He said it seeing the man at the door. When the man sat down he was open and easy with him to his face. Afterwards Aisha asked. He told her the worst of people in station on the Day of Resurrection is the one people abandon out of fear of his foulness.
The full narration
Narrated 'Aisha: A man asked permission to enter upon the Prophet. When the Prophet (ﷺ) saw him, he said, "What an evil brother of his tribe! And what an evil son of his tribe!" When that man sat down, the Prophet (ﷺ) behaved with him in a nice and polite manner and was completely at ease with him. When that person had left, 'Aisha said (to the Prophet). "O Allah's Apostle! When you saw that man, you said so-and-so about him, then you showed him a kind and polite behavior, and you enjoyed his company?" Allah's Messenger (ﷺ) said, "O 'Aisha! Have you ever seen me speaking a bad and dirty language? (Remember that) the worst people in Allah's sight on the Day of Resurrection will be those whom the people leave (undisturbed) to be away from their evil (deeds)
Source
Ṣaḥīḥ al-Bukhārī · 6032
- Recorded in Ṣaḥīḥ al-Bukhārī, whose narrations are accepted as authentic