He commanded His Messenger to disavow himself from their religion completely

. Allah said,

﴿لاَ أَعْبُدُ مَا تَعْبُدُونَ ﴾

(I worship not that which you worship.) meaning, statues and rival gods.

﴿وَلاَ أَنتُمْ عَـبِدُونَ مَآ أَعْبُدُ ﴾

(Nor will you worship whom I worship.) and He is Allah Alone, Who has no partner. So the word Ma (what) here means Man (who). Then Allah says,

﴿وَلاَ أَنَآ عَابِدٌ مَّا عَبَدتُّمْ وَلاَ أَنتُمْ عَـبِدُونَ مَآ أَعْبُدُ ﴾

(And I shall not worship that which you are worshipping. Nor will you worship whom I worship.) meaning, `I do not worship according to your worship, which means that I do not go along with it or follow it. I only worship Allah in the manner in which He loves and is pleased with.' Thus, Allah says,

﴿وَلاَ أَنتُمْ عَـبِدُونَ مَآ أَعْبُدُ ﴾

(Nor will you worship whom I worship.) meaning, `you do not follow the commands of Allah and His Legislation in His worship. Rather, you have invented something out of the promptings of your own souls.' This is as Allah says,

﴿إِن يَتَّبِعُونَ إِلاَّ الظَّنَّ وَمَا تَهْوَى الاٌّنفُسُ وَلَقَدْ جَآءَهُم مِّن رَّبِّهِمُ الْهُدَى﴾

(They follow but a guess and that which they themselves desire, whereas there has surely come to them the guidance from their Lord!) (53:23) Therefore, the disavowal is from all of what they are involved. For certainly the worshipper must have a god whom he worships and set acts of worship that he follows to get to him. So the Messenger and his followers worship Allah according to what He has legislated. This is why the statement of Islam is "There is no God worthy of being worshipped except Allah, and Muhammad is the Messenger of Allah.'' This means that there is no (true) object of worship except Allah and there is no path to Him (i.e., way of worshipping Him) other than that which the Messenger came with. The idolators worship other than Allah, with acts of worship that Allah has not allowed. This is why the Messenger said to them,

﴿لَكُمْ دِينُكُمْ وَلِىَ دِينِ ﴾

(To you be your religion, and to me my religion.) This is similar to Allah's statement,

﴿وَإِن كَذَّبُوكَ فَقُل لِّى عَمَلِى وَلَكُمْ عَمَلُكُمْ أَنتُمْ بَرِيئُونَ مِمَّآ أَعْمَلُ وَأَنَاْ بَرِىءٌ مِّمَّا تَعْمَلُونَ ﴾

(And if they belie you, say: "For me are my deeds and for you are your deeds! You are innocent of what I do, and I am innocent of what you do!'') (10:41) and He said,

﴿لَنَآ أَعْمَـلُنَا وَلَكُمْ أَعْمَـلُكُمْ﴾

(To us our deeds, and to you your deeds.) (28:55) Al-Bukhari said, "It has been said,

﴿لَكُمْ دِينَكُمْ﴾

(To you be your religion.) means disbelief.

﴿وَلِىَ دِينِ﴾

(and to me my religion.) means, Islam. This is the end of the Tafsir of Surat Qul ya Ayyuhal-Kafirun.