Sahih Bukhari Volume 6, Book 65, Hadith 4527

فَقَالَ قَالَتْ عَائِشَةُ مَعَاذَ اللَّهِ، وَاللَّهِ مَا وَعَدَ اللَّهُ رَسُولَهُ مِنْ شَىْءٍ قَطُّ إِلاَّ عَلِمَ أَنَّهُ كَائِنٌ قَبْلَ أَنْ يَمُوتَ، وَلَكِنْ لَمْ يَزَلِ الْبَلاَءُ بِالرُّسُلِ حَتَّى خَافُوا أَنْ يَكُونَ مَنْ مَعَهُمْ يُكَذِّبُونَهُمْ، فَكَانَتْ تَقْرَؤُهَا ‏{‏وَظَنُّوا أَنَّهُمْ قَدْ كُذِّبُوا‏}‏ مُثَقَّلَةً‏.

He said, "'Aisha said, 'Allah forbid! By Allah, Allah never promised His Apostle anything but he knew that it would certainly happen before he died. But trials were continuously presented before the Apostles till they were afraid that their followers would accuse them of telling lies. So I used to recite: "Till they (come to) think that they were treated as liars." reading 'Kudh-dhibu with double 'dh.'