The Right Man for Each Task

Allah (swt) gave every one of these anbiyāʾ all of the qualities he needed for the specific purpose he was going to fulfil. Allah (swt) gave Mūsā a very strong and powerful personality, because he was going to be dealing with a very stubborn people, Banū Isrāʾīl. So Allah (swt) gave him a very strong personality, and a strong body, and a strong character, and a strong presence. When Mūsā was there, they would not have dared to do what they did in front of Hārūn.

And Allah (swt) gave Hārūn the qualifications he needed as a wazīr and advisor for his brother: He gave him the ability to speak. Mūsā said: my brother Hārūn is more eloquent, or clearer in his speech — to be an assistant for his brother. When Mūsā was absent, Banū Isrāʾīl were about to kill Hārūn, so Hārūn had to calm things down until his brother came back. If he had tried to enforce the law and prevent them from worshipping the calf, that would have caused a rift and a dispute among Banū Isrāʾīl, and the problem could have got out of control.

And we know that when you make al-nahy ʿan al-munkar, you want to make sure that it will not cause a bigger munkar. When you are preventing evil, one of the rules of preventing evil is that it should not cause a bigger evil. So Hārūn was not approving of the worship of the calf. He told his people — because he has to make bayān; he cannot keep quiet and then say this is ḥikmah; no, he has to tell the people that this is wrong — and he told them that it was wrong: your Lord is Allah, al-Raḥmān. But he waited until his brother came back, and then he would leave it in the hands of his brother Mūsā.