Hadith 1021:6
Aswad ibn Amir narrated to us, Sharik narrated to us, from Muhajir al-Sa’igh, from a man—whom he did not name—among the companions of the Prophet, may Allah bless him and grant him peace, that he heard a man—meaning the Prophet, may Allah bless him and grant him peace—reciting: "Say, 'O disbelievers,'" and he said: "As for this one, he has been absolved of shirk (polytheism)." And he heard another reciting: "Say, 'He is Allah, [who is] One,'" and he said: "As for this one, he has been forgiven."
حدثنا أسود بن عامر، حدثنا شريك، عن مهاجر الصائغ، عن رجل لم يسمه من أصحاب النبي صلى الله عليه وسلم، أنه سمع رجلا يعني النبي صلى الله عليه وسلم يقرأ: قل يا أيها الكافرون فقال: " أما هذا فقد برئ من الشرك "، وسمع آخر وهو يقرأ: قل هو الله أحد فقال: " أما هذا فقد غفر له "