Narrated Aisha, Ummul Mu'minin: The Prophet (ﷺ) went out from me, while he was happy, but he returned to me while he was sad. He said: I entered the Ka'bah, I know beforehand about my affair what I have come to know later I would not have entered it. I am afraid I have put my community to hardship.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ دَاوُدَ، عَنْ إِسْمَاعِيلَ بْنِ عَبْدِ الْمَلِكِ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي مُلَيْكَةَ، عَنْ عَائِشَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم خَرَجَ مِنْ عِنْدِهَا وَهُوَ مَسْرُورٌ ثُمَّ رَجَعَ إِلَىَّ وَهُوَ كَئِيبٌ فَقَالَ " إِنِّي دَخَلْتُ الْكَعْبَةَ وَلَوِ اسْتَقْبَلْتُ مِنْ أَمْرِي مَا اسْتَدْبَرْتُ مَا دَخَلْتُهَا إِنِّي أَخَافُ أَنْ أَكُونَ قَدْ شَقَقْتُ عَلَى أُمَّتِي " .
sunnah.com