Prophet Shu'ayb ﷺ was sent to the people of Madyan (in the north-west Arabian Peninsula) and to the people of Al-Aykah. These peoples were notorious for fraud in trade — giving short measure, using false weights, and deceiving in business.
Shu'ayb ﷺ was known as the "Khatib al-Anbiya'" — the orator of the prophets — for his eloquent speech and persuasive preaching. He warned them to deal justly and abandon corrupt practices. After prolonged rejection, divine punishment came: a tremendous thundering blast destroyed the people of Madyan, and a scorching heat destroyed Al-Aykah.