Harun was the prophet who was Musa’s brother and spokesman. In Islamic tradition, Harun is the Arabic name for Aaron, the elder brother of Musa (Moses) and a prophet in his own right.
The Qur’an describes Musa asking God to appoint Harun as his helper, strengthen his mission through him, and give him eloquence in speech. This matters because Musa feared that difficulty in expression would hinder his message to Pharaoh. Harun therefore accompanied him when they confronted Pharaoh and called the Israelites to worship God.
A common mix-up is confusing Harun with Yahya, the son of Zakariyya, or with Isa, whose mother Maryam is sometimes described as belonging to a priestly line associated with Harun. Harun also briefly led the Israelites while Musa was away receiving the tablets. During that absence, he opposed the making of the golden calf but could not prevent the people from following it.
The Qur’an presents both brothers as chosen prophets, while Islamic scholarship discusses details of their chronology and family relationships alongside Biblical tradition.