It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that a man from the Ansar embraced Islam, then apostatized and joined the polytheists. Then he regretted it and sent word to his people: Ask the Messenger of Allah (peace and blessings be upon him): Is there any room for repentance for me? So these verses were revealed: "How shall Allah guide a people who disbelieved after their belief" up to His saying: "Except those who repent after that and reform themselves, for indeed Allah is Most Forgiving, Most Merciful." [Al Imran: 86-89] . The narrator said: Then his people sent word to him, and he embraced Islam (again). This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) that whenever the Prophet (peace and blessings be upon him) felt danger from a people, he would make this supplication: 'Allahumma inna naj'aluka fi nuhurihim, wa na'udhu bika min shururihim' (O Allah, we place You as a shield against them, and we seek refuge in You from their evils). This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), and my strongest assumption is that they did not record it.

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) used to make this supplication: 'Allahumma amti'ni bi-sam'i wa basari, waj'alhuma al-waritha minni; Allahumma-nsurni 'ala 'aduwwi, wa arini fihi tha'ri' (O Allah, let me benefit from my hearing and my sight (throughout my life) and make them my heir; O Allah, help me against my enemy and grant me victory over him, so that I see my revenge on him with my own eyes). This hadith is sahih (authentic) on the condition of Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.