بسم الله الرحمن الرحيم

Shaikh Salih al Fawzaan حفظه الله comments regarding His Statement (The Most High):

مَا كَانَ لِبَشَرٍ أَن يُؤۡتِيَهُ ٱللَّهُ ٱلۡكِتَٰبَ وَٱلۡحُكۡمَ وَٱلنُّبُوَّةَ ثُمَّ يَقُولَ لِلنَّاسِ كُونُواْ عِبَادٗا لِّي مِن دُونِ ٱللَّهِ وَلَٰكِن كُونُواْ رَبَّٰنِيِّـۧنَ بِمَا كُنتُمۡ تُعَلِّمُونَ ٱلۡكِتَٰبَ وَبِمَا كُنتُمۡ تَدۡرُسُونَ

It is not (possible) for any human being to whom Allah has given the Book and Al-Hukma (the knowledge and understanding of the laws of religion, etc.) and Prophethood to say to the people: “Be my worshippers rather than Allah’s.” On the contrary (he would say): “Be you Rabbaaniyun (learned men of religion who practise what they know and also preach others), because you are teaching the Book, and you are studying it.” (Surah Aali-Imraan:79)

What is understood from this verse is that the path of the prophets and their followers is one, undeviating, from the first of them (prophets) to the last of them. All of prophets brought with them the command of tawheed and the forbiddance of shirk, Allah (The Most High) said:

وَلَقَدۡ بَعَثۡنَا فِي كُلِّ أُمَّةٖ رَّسُولًا أَنِ ٱعۡبُدُواْ ٱللَّهَ وَٱجۡتَنِبُواْ ٱلطَّٰغُوتَۖ

And verily, We have sent among every Ummah (community, nation) a Messenger (proclaiming): “Worship Allah (Alone), and avoid (or keep away from) Taghut (all false deities, etc.i. e. do not worship Taghut besides Allah).”  Surah An-Nahl, Ayah 36

And similarly the followers of the messengers, they also carry out this duty which the messengers brought with them, and it (the duty) is the calling to the worship of Allah alone and not ascribing partners to him in worship and leaving the worship of other than him, just like what He صلى الله عليه وسلم  said:

وإن العلماء ورثة الأنبياء وإن الأنبياء لم يورثوا دينارًا ولا درهما وإنما ورثوا العلم‏.‏ فمن أخذه أخذ بحظ وافر……

The scholars are the heirs of the Prophets who bequeath neither dinar nor dirham but only that of knowledge; and he who acquires it, has in fact acquired an abundant portion. (1)

Min Ahkhaam al-Qur’aan by Shaikh Salih al Fawzaan حفظه الله vol.1 pg. 24.
1) Abu Dawud (3641), TIirmidhi (2682), Ibn Maajah (223) Narrated by Abu Darda  رضي الله عنه