Shaykh ʿUbayd al-Jābirī comments on the verse below, clarifying an existing doubt:
شَهِدَ اللَّهُ أَنَّهُ لَا إِلَٰهَ إِلَّا هُوَ وَالْمَلَائِكَةُ وَأُولُو الْعِلْمِ قَائِمًا بِالْقِسْطِ ۚ لَا إِلَٰهَ إِلَّا هُوَ الْعَزِيزُ الْحَكِيمُ
Allāh bears witness that none has the right to be worshipped but Him; and likewise, the angels and the people of knowledge bear witness: He who maintains justice, none has the right to be worshipped but Him, the All Mighty, the All Wise.
[Sūrah al-ʿImrān, 3:18]
Present in this verse is a refutation of some of those who ascribe to the daʾwah, who says:
The caller (dāʿī) is better than the scholar. They use the argument that the caller is like the rain cloud, traveling from place to place, and everyone benefits from it [i.e. the rain]. While the scholar is like a well, no one drinks from it except those who travel to it. Glorified is Allāh the Exalted! Are they more knowledgeable or Allāh? Who are the ones who testify to the oneness of Allāh [in this verse], the scholar or the caller? The scholar! Who are the inheritors of the prophets? The scholars, or the callers who travel from place to place? Some of them [i.e. callers] are not even able to recite Sūrah al-Fātiḥah correctly and do not know the pillars of Islām. Corrupt reasoning and misinterpretation of the speech of Allāh and His Messenger (ﷺ) is the way of the people of innovation and desires; so be warned.
 Itḥāf al-ʿUqūl, pg. 89-90
Translated by: Munīb al-Ṣumālī