It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that a man said: "O Messenger of Allah! I have not left any need or desire (of sin), small or great, without committing it." He (peace and blessings be upon him) asked: "Do you testify that there is no god but Allah and that Muhammad is the Messenger of Allah?" He said: "Yes." He (peace and blessings be upon him) said: "Then indeed this (testimony of faith) encompasses all of those (sins) (that is, it wipes them out)."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Thabit al-Bunani (may Allah have mercy on him) except Mastur bin Abbad (may Allah have mercy on him)."
Hadith Referenceالمعجم الأوسط / باب الميم / 7077
Hadith Takhrij«أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 1773، 1774، 1775، وأبو يعلى فى «مسنده» برقم: 3433، والبزار فى «مسنده» برقم: 6887، وابن حجر فى «المطالب العالية» برقم: 2863 / 2، والطبراني فى «الصغير» برقم: 1025»