Surah Nas 114
Al-Nās ("Mankind") is the 114th and last chapter (sūrah) of the Qur'an. It is a short six-verse invocation, asking God for protection from the Devil (Iblis). The chapter takes its name from the word "people" or "mankind" (al-nās), which recurs throughout the chapter. Together with the preceding chapter, Al-Falaq ("Daybreak"), they are known as "the Refuges" (Al-Mu'awwidhatayn); dealing with roughly the same theme, they form a natural pair.
Regarding the timing and contextual background of the supposed revelation (asbāb al-nuzūl), it is an earlier "Meccan surah", which means it is believed to have been revealed in Mecca, instead of later in Medina.
There is a Sunnah tradition of reading this chapter for the sick or before sleeping.