They were known as ʿAnzah—not, however, the later tribe of ʿAnzah ibn Asad ibn Rabīʿah ibn Nizār ibn Maʿd ibn ʿAdnān, for that line emerged many ages after them; Allah knows best.
In the ḥadīth of Abū Dharr recorded by Ibn Ḥibbān in his Ṣaḥīḥ under the chapter on the prophets and messengers, he said:
“Four of the prophets were Arabs: Hūd, Ṣāliḥ, Shuʿayb, and your Prophet, O Abū Dharr.” (1)
Some of the early scholars therefore called Shuʿayb “the orator of the prophets,” because of his eloquence, lofty diction, and persuasive speech in inviting his people to believe in his message. Ibn Isḥāq ibn Bishr narrates—through Juwaybir and Muqātil, from al-Ḍaḥḥāk, from Ibn ʿAbbās—that the Messenger of Allah ﷺ, whenever he mentioned Shuʿayb, would say, “That is the orator of the prophets.” (2)
The people of Midian were disbelievers who blocked the highways, terrorised travellers, and worshipped the Thicket (al-Aykah)—a tree surrounded by a dense copse (3). They were among the worst of people in their commercial dealings, depriving others of measure and weight, cheating in both: they would take the surplus and hand over the deficient. Allah therefore sent to them one of their own—the Messenger of Allah, Shuʿayb (peace be upon him). He summoned them to worship Allah alone with no partner and forbade them these disgraceful acts: defrauding people of their goods and frightening them on roads and pathways. Some believed in him, but most rejected him, until Allah visited upon them a severe punishment; He is the Protecting Friend, the Praiseworthy.
The Exalted says: “And to Midian We sent their brother Shuʿayb, who said, ‘My people, worship Allah; you have no deity but Him. A clear proof has come to you from your Lord.’” (al-Aʿrāf 7:85). That is, an evident sign and conclusive proof of the truth of what I have brought you and that He has sent me—the miracles Allah caused at his hands, whose details have not reached us, though these words indicate them in general.
“So give full measure and weight, and do not deprive people of their due, nor spread corruption on the earth after it has been set right.” (al-Aʿrāf 7:85). He commanded them to act justly and forbade them to commit injustice, threatening them should they do otherwise (4). He said: “That is better for you, if you are believers. And do not sit on every road”—that is, every route—“threatening people” (al-Aʿrāf 7:85–86); meaning, threatening them with the seizure of their property through levies and the like, and frightening travellers along the highways.
Al-Suddī, in his Tafsīr, reporting from the Companions, said about the words, “Do not sit on every road, threatening people,” that they used to exact tithes from the wealth of passers-by.