Prophets Yaḥyā and ʿĪsā: Part 1 — Five Commands, a Palm Trunk and a Voice From the Cradle
Section 22 of 25 · Lives of the Prophets
O Sister of Hārūn
And they also said: yā ukhta Hārūn, O sister of Hārūn. Who is Hārūn? By the way, the Jews in the time of the Messenger of Allah*** said: see, the Messenger of Allah does not know what he's talking about; he's saying that Maryam is the sister of Hārūn, and between them are hundreds of years. So what does this mean — yā ukhta Hārūn, O sister of Hārūn? It has one of two meanings.
One of them is that she had a brother whose name was Hārūn. And when they said that your father and your mother did not commit zinā, they completed the rest of the family by mentioning her brother, who was also a righteous man. In other words, they're telling her: all of your family are righteous; what's wrong with you? This is one meaning.
And the Messenger of Allah (peace be upon him) says that those people used to name their children according to the names of their anbiyāʾ. The Messenger of Allah says in the hadith: they used to name their children after their anbiyāʾ. And therefore it's also something recommended to do, to name after the anbiyāʾ. The Messenger of Allah (peace be upon him) named his son Ibrāhīm, which is the father of the Messenger of Allah (peace be upon him)****. This is one meaning.
The second meaning would be that they were bringing up Hārūn — the Nabī, Hārūn. Because Āl ʿImrān are from the descendants of Hārūn: they are descendants of Dāwūd, and Dāwūd was a descendant of Hārūn*****. Subḥān Allāh, Allah (swt) put the prophethood in Banū Isrāʾīl not in Mūsā, but in the lineage of Hārūn. So in other words, they are bringing up the fact that you are from a righteous family; you are from the righteous family of Hārūn — what are you doing?
So you might ask the question: how come they said sister of Hārūn? Why didn't they say son of Hārūn? In the Qur'an it says akhā ʿĀd, the brother of ʿĀd. When you are part of a family, you are called the brother of that family; in the Arabic language, that's how you say it. So Hūd, in the Qur'an, is referred to as akhā ʿĀd, the brother of ʿĀd, even though he was a descendant of ʿĀd, from the people of ʿĀd. So it would mean: you are from the righteous family of Hārūn; your father and your mother don't commit zinā; what have you done?