Surahs 113 (al-Falaq) and 114 (an-Nas) are called the Mu'awwidhatayn — 'the two seekings of refuge' — and have been recited together for protection in Muslim practice from the earliest period. Sahih hadith preserved by both Bukhari and Muslim describe the Prophet reciting these two surahs every night before sleep, blowing into his cupped hands and wiping them over his body, and instructing his community to do the same. They function liturgically as the closing of the Quran in mushaf order and devotionally as the closing of the day. Their pairing is so habitual that they are rarely cited separately in classical practice.Sahih Bukhari Kitab al-Da'awat and Sahih Muslim on the Prophet's nightly recitation; Ibn Kathir on the Mu'awwidhatayn pairing.
A classical wrinkle worth knowing: 'Abdullah ibn Mas'ud, one of the Prophet's most prominent companions and a major reciter of the Quran, did not include the Mu'awwidhatayn in his personal mushaf. He is reported to have considered them prophetic du'as (supplications) given for use rather than divine revelation in the strict sense. The jumhur — the overwhelming majority of the early Muslim community — rejected this view; the surahs are unambiguously canonical in every accepted Quranic codex from 'Uthman onward. But Ibn Mas'ud's position is preserved as a reminder that the canonization of even the closing surahs was an early-community decision, not a self-evident given.al-Suyuti al-Itqan fi 'Ulum al-Quran on Ibn Mas'ud's mushaf and the jumhur response; Ibn Hanbal Musnad.