The combining of the Prophet’s (peace and blessings be upon him) command to Mu‘adh to begin with the call to the two testimonies first, and his (peace and blessings be upon him) saying to him, “The best of your deeds is prayer”

Question : May Allah bless you. When the Prophet (peace and blessings be upon him) sent Mu‘adh, he meant to say: The first thing you call them to is the testimony that there is no god but Allah and that Muhammad is the Messenger of Allah. Yes. And he did not say that any deed requires prayer.

Answer : Mu‘adh ibn Jabal was not sent alone; he was accompanied by a group. He said: “The most important thing I sent you with is prayer.” This means that he wanted the soldiers with him to establish prayer. As for these regions, the most important thing we call them to is tawhid (the oneness of Allah), the testimony of Allah, and He is the best Disposer of affairs.