Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates from Sayyiduna Abu Qatadah (may Allah be pleased with him) that he said: the Messenger of Allah (peace and blessings be upon him) said: "All of my Ummah will be pardoned except the one who does a (bad) deed at night, and then in the morning, when his Lord has concealed it for him, he (himself tells others): 'O so-and-so, last night I did such and such'; or he (peace and blessings be upon him) said: He spent the night with his Lord concealing his fault, and when morning came he himself exposed the concealment of Allah (that He had granted him)."
This hadith is not narrated from Sayyiduna Abu Qatadah (may Allah be pleased with him) except with this chain, and al-Hasan bin Ali al-Hulwani (may Allah have mercy on him) is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب العين / 4498
Hadith Takhrij«أخرجه الطبراني فى «الصغير» برقم: 632»