Tafsir of Al-Anbiya' 21:106

Verily, in this (the Qur'an) there is a plain Message for people who worship Allah. means, `in this Qur'an which We have revealed to Our servant Muhammad, there is a plain Message which is beneficial and is sufficient for a people who worship Allah.' This refers to those who worship Allah in the manner which He has prescribed and which He loves and is pleased with, and they would rather obey Allah than follow the Shaytan or their own desires. Muhammad is a Mercy to the Worlds Allah says:

وما أرسلناك إﻻ رحمة للعالمين