Al-Falaq and the following An-Nas are known together as al-Mu'awwidhatan, 'the two of seeking refuge,' revealed as a means of protection. Tradition reports the Prophet reciting them, blowing into his hands and wiping over himself each night and during illness. Al-Falaq's naming of specific harms, darkness, sorcery, envy, made it a standard recitation in the Islamic practice of seeking God's protection (ruqya).
Classical commentary connects the specific harms named in Al-Falaq, the darkness of night, those who blow on knots, and the envier, to a real, if disputed, episode in the Prophet's biography: several early sources report that he was afflicted by sorcery involving knots tied by a Jewish man named Labid ibn al-Asam, discovered and undone after these two surahs were revealed as remedy, an account the major classical commentators report without exception, though it has drawn theological discussion in later Islamic thought over how to reconcile a prophet being affected by sorcery with the doctrine of prophetic protection from error, a question apologetic and theological writing continues to address rather than one the classical sources themselves treated as settled by the hadith alone. However the episode is read, the two surahs together remain, in ordinary devotional practice, the standard closing recitation of a nightly ritual of protection distinct from formal prayer.