Harun prohibits them from worship of Calf and the Persistence of the Children of Israel in doing so

Allah, the Exalted, informs of Harun's attempt to prohibit them from worshipping the calf and his telling them that this was only a test for them. He told them that their Lord was the Most Beneficent, Who created everything and decreed for everything its just measure. He is the Owner of the Mighty Throne, the One Who does whatever He wants.

فَاتَّبِعُونِى وَأَطِيعُواْ أَمْرِى

Commentary

When the Bani Isra'il were smitten with the mischief of calf-worship Sayyidna Harun (علیہ السلام) as the deputy of Sayyidna Musa (علیہ السلام) remonstrated with them but to no avail. They split into three factions. Those who remained loyal to Sayyidna Harun (علیہ السلام) and refused to be misled by Samiri and who numbered, according to Qurtubi, twelve thousand. The second faction adopted calf-worship with the reservation that if Sayyidna Musa (علیہ السلام) ، on his return, forbade them they would give it up. The third faction consisted of zealots who believed that Sayyidna Musa علیہ السلام would approve of their action and would himself join them in calf-worship but even if he did not, they themselves would never give up their new faith. When Sayyidna Musa (علیہ السلام) returned to his people he rebuked them for the mischief they had caused (as related in the earlier verses). Then he turned to Sayyidna Harun (علیہ السلام) and in a rage seized him by his beard and the hair of his head. He asked him that when the unbelief (کُفر) of the Bani Isra'il had become obvious, why he did not follow him to the Tur mountain and why he disobeyed his orders.