Musa was sent with the Message of Tawhid to Fir`awn and His Chiefs

Allah tells,

وَلَقَدْ أَرْسَلْنَا مُوسَى بِآيَاتِنَا إِلَى فِرْعَوْنَ وَمَلَئِهِ فَقَالَ إِنِّي رَسُولُ رَبِّ الْعَالَمِينَ ﴿٤٦﴾

فَلَمَّا جَاءهُم بِآيَاتِنَا إِذَا هُم مِّنْهَا يَضْحَكُونَ ﴿٤٧﴾

And indeed We did send Musa with Our Ayat to Fir`awn and his chiefs. He said: "Verily, I am a Messenger of the Lord of all that exists.''

But when he came to them with Our Ayat, behold, they laughed at them.

Here Allah tells us about His servant and Messenger Musa, peace be upon him, and how He sent him to Fir`awn and his chiefs. That is, his governors, ministers, leaders and followers among the Egyptians and the Children of Israel.

Allah sent him to call them to worship Allah alone, with no partner or associate, and to forbid them from worshipping anything other than Him. He sent him with mighty signs, such as his hand and his staff, other signs such as the flood, locusts, Qummal, frogs and blood, and the loss of their crops and lives. Yet despite all that they remained arrogant and stubbornly refused to follow him; they rejected his message and made fun of it, and laughed at the one who had brought it.