Та Ха 20:86

When Almighty God informed Moses that his community had gone astray, he returned to his community very emotionally upset. He reminded his people that God had only recently showered His blessings on them and had revealed His many signs to them. So, how was it that they had forgotten everything so quickly and gone astray? Moses had gone to receive revelations from God for the Israelites and in the meantime the Israelites had started indulging in the worship of false deities at the instigation of certain misguided persons. This shows how deeply the polytheistic atmosphere of Egypt had influenced the Israelites and why it had become necessary to take them away from Egypt in order to restore them to the worship of the one God. Whatever Moses did with regard to Pharaoh was in connection with his dawah mission, and whatever he did with regard to the Israelites was in the context of safeguarding true religion. He performed both these tasks simultaneously. This shows the importance of both these tasks. If the Muslims had gone astray, dawah activity could not be stopped on that account and, similarly, if dawah work had to be done, it was not to be at the cost of internal reform.