The Meeting of the Two Parties, Musa's Propagation of the Message and the Magicians

Allah, the Exalted informs that when Fir`awn and Musa agreed to an appointed meeting at a specified place and time, Fir`awn began to gather some magicians from the cities of his kingdom. Every person who had any affiliation with magic at that time was summoned, and magic was very widespread and in demand at that time. This is as Allah says,

وَقَالَ فِرْعَوْنُ ائْتُونِى بِكُلِّ سَـحِرٍ عَلِيمٍ

فَأَجْمِعُوا كَيْدَكُمْ ثُمَّ ائْتُوا صَفًّا (So, make your plot firm and forth in one row - 20:64). Formation of troops in ranks in battle has an unsettling effect on the enemy, so the Egyptian magicians arranged themselves in ranks for the contest.