[Pooya/Ali Commentary 21:107] It is stated in the Quran that prophets of Allah were sent to every people in every age, then as a culmination the Holy Prophet was sent to mankind as a mercy unto the worlds with a universal message. In verse 81 of Ali Imran all the prophets of Allah have accepted the Holy Prophet as their supreme leader, therefore he is the only leader their followers should also obey and follow. Keeping this fact in view the Holy Prophet has been introduced to all human beings till eternity as the mercy unto the worlds to whom the final book of Allah, the Quran, was revealed and who was entrusted with the perfected and completed religion of Allah to be the law and guidance for all mankind for ever (see commentary of Ma-idah: 5 and 67 The word alamin (the worlds) encompasses all that has been created by Allah and He has not created the universe out of fun (verse 16 of this surah). Aqa Mahdi Puya says: By presenting the Holy Prophet as the mercy unto the worlds it has been clearly asserted that he is the first and the foremost in the order of creation who was selected to convey the mercy of Allah to every created being. The entire existence of the Holy Prophet is the first and the continuous manifestation of the rububiyat of the rabbul alamin. The whole process of creation implies the circular process of descension and ascension of the person of the Holy Prophet for the purpose of universal blessings.