Establish prayer at the decline of the sun [from its meridian] until the darkness of the night and [also] the Qur'an of dawn. Indeed, the recitation of dawn is ever witnessed. 78 As for the night there is a voluntary deed for you to keep vigil in part it. Perhaps your Lord will raise you to a praiseworthy station. 79 And say [in thy prayer]: "O my Sustainer! Cause me to enter [upon whatever I may do] in a manner true and sincere, and cause me to leave [it] in a manner true and sincere, and grant me, out of Thy grace, sustaining strength!" 80 And say: "Truth (i.e. Islamic Monotheism or this Quran or Jihad against polytheists) has come and Batil (falsehood, i.e. Satan or polytheism, etc.) has vanished. Surely! Batil is ever bound to vanish." 81 And We reveal by means of the Qur'an that which is a healing and a mercy unto the believers, and it only increaseth the wrong-doers in loss. 82 Yet when We bestow favors upon mankind he turns his back and withdraws to one side. But when evil befalls him, he despairs. 83 Say: Every one acts according to his manner; but your Lord best knows who is best guided in the path. 84