Tafsir of Al-Furqan 25:60

وإذا قيل لهم اسجدوا للرحمن قالوا وما الرحمن

And when it is said to them: "Prostrate yourselves to Ar-Rahman!'' They say: "And what is Ar-Rahman!'' meaning: we do not know Ar-Rahman. They did not like to call Allah by His Name Ar-Rahman (the Most Gracious), as they objected on the day of (the treaty of) Al-Hudaybiyyah, when the Prophet told the scribe:

اكتب بسم الله الرحمن الرحيم

Write: "In the Name of Allah, Ar-Rahman (the Most Gracious), Ar-Rahim (the Most Merciful).'' They said, "We do not know Ar-Rahman or Ar-Rahim. Write what you used to write: `Bismika Allahumma (in Your Name, O Allah).''' So Allah revealed the words:

قل ادعوا الله أو ادعوا الرحمن أيا ما تدعوا فله اﻻسماء الحسنى

Say: "Invoke Allah or invoke Ar-Rahman, by whatever name you invoke Him (it is the same), for to Him belong the Best Names. (17:110) meaning, He is Allah and He is the Most Gracious. And in this Ayah, Allah said:

وإذا قيل لهم اسجدوا للرحمن قالوا وما الرحمن

And when it is said to them: "Prostrate yourselves to Ar-Rahman!'' They say: "And what is the Ar-Rahman!'' meaning: we do not know or approve of this Name.

أنسجد لما تٲمرنا

Shall we fall down in prostration to that which you command us! means, "Just because you tell us to!''

وزادهم نفورا

And it increases in them only aversion. As for the believers, they worship Allah Who is the Most Gracious, Most Merciful, and they attribute divinity to Him Alone and prostrate to Him. The scholars, agree that it is allowed and approved for the reader and the listener to prostrate when he reaches this mention of prostration in Surah Al-Furqan, and Allah knows best