Answered by Shaykh Yusuf Weltch
I sang a song in praise of the Prophet (Allah bless him and give him peace) in which the lyrics call Him “Shehenshah e deen (King of all kings).” Have I committed shirk (associating partners with Allah)?
In the Name of Allah, the Most Merciful and Compassionate
Singing a song in which the Prophet (Allah bless him and give him peace) is called King of kings (of the religion) is not shirk.
You did not translate the part “of the religion,” although it is in the Urdu transliteration (e deen) that you wrote in your question.
Describing anyone other than Allah Most High as king of kings is strictly prohibited. However, if it is conditioned and qualified, such as “the king of kings of created beings,” the ruling differs.
Without qualifying the statement, calling anyone king of kings is prohibited because this is an attribution that belongs only to Allah Most High. The Messenger of Allah (Allah bless him and give him peace) said, “The most abased name in the sight of Allah on the Day of Judgment is that of a person called ‘king of kings.’” [Bukhari & Muslim]
Sufyan added, narrating from others that the king of kings is Shahan shah (i.e., in other languages). [Bukhari]
Even though the qualification of the king of kings by adding king of kings (in the religion) is not the same as saying it without the qualification – it is best to abstain from such statements.
Despite this, singing something is not the same as believing something. Even if the phrase was not qualified with (in the religion), you singing it does not necessitate that you are affirming it and thus, it is still not shirk.
Allah knows best
[Shaykh] Yusuf Weltch