It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When a sin remains hidden, it harms only the one who commits it; but when it becomes open and is not changed, it harms the general public."
No one narrated these two hadiths from al-Awza'i (may Allah have mercy on him) except Marwan bin Salim (may Allah have mercy on him), and Abu Hammam (may Allah have mercy on him) is alone in narrating them.
Hadith Referenceالمعجم الأوسط / باب العين / 4770
Hadith Gradingمحدثین:إسناده ضعيف جدًّا، فيه مروان بن سالم الغفاري متروك
Hadith Takhrij«قال الهيثمي: فيه مروان بن سالم الغفاري وهو متروك «مجمع الزوائد ومنبع الفوائد، ج 7، ص 268»»