Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates this statement of the Prophet (peace and blessings be upon him): "Indeed, every deed has a period of enthusiasm, and every enthusiasm has a period of slackening. When the doer remains upright and adopts moderation, then have hope for him; but if he is pointed at with a finger (i.e., becomes notorious), then do not count him among any number."
Hadith Referenceصحیح ابن حبان / كتاب البر والإحسان / 349
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيحسن - «الصحيحة» (2850)، «التعليق الرغيب» (1/ 46).فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده قوي.