It is the system of Allah Ta‘ala that when he creates something, he also creates its opposite. Allah Ta‘ala states:
وَ مِنۡ کُلِّ شَیۡءٍ خَلَقۡنَا زَوۡجَیۡنِ لَعَلَّکُمۡ تَذَکَّرُوۡنَ ﴿۴۹﴾
And from everything We have created pairs so that you may comprehend (the perfection of the Creator). (Surah Zaariyaat v. 49)
Hence, just as there is a Musa for every Fir‘aun, there must be a Fir‘aun for every Musa. Nevertheless, since things may be understood and recognized by viewing their opposites, we will next present a brief outline of each of the arch-enemies of Rasulullah (sallallahu ‘alaihi wasallam).
(Extracted from Seeratul Mustafa 1/210-211)