Ibn Hajar reported: Abdullah ibn Rawahah, may Allah be pleased with him, said, “The parable of faith is that of a shirt. You may not be wearing it and then you put it on, or you may be wearing it and then you take it off.”
Source: Fatḥ al-Bārī 12/61
عن ابن حجر قال عَبْدِ اللَّهِ بْنِ رَوَاحَةَ رضي الله عنه مَثَلُ الْإِيمَانِ مَثَلُ قَمِيصٍ بَيْنَمَا أَنْتَ مُدْبِرٌ عَنْهُ إِذْ لَبِسْتَهُ وَبَيْنَمَا أَنْتَ قَدْ لَبِسْتَهُ إِذْ نَزَعْتَهُ
12/61 فتح الباري شرح صحيح البخاري كتاب الحدود