What is the meaning of publicizing sins? And is speaking about a past sin without boasting considered publicizing it?

The public disclosure mentioned by the Prophet, peace and blessings be upon him, in the hadith agreed upon by Abu Hurairah, may Allah be pleased with him, means that a man commits an act at night, and Allah has concealed it for him, then he wakes up and says: "Last night I did such and such," thereby revealing Allah’s concealment from him. Therefore, a person should not mention the sins that Allah has concealed for him.