Surely in that (which took place between Moses and Pharaoh) there is a sign (a great, important lesson). Most of them (the Pharaoh’s people) were not believers
Indeed, there is a miracle – a lesson – in this! Yet most of them have not believed.
Sayyed Abbas Sadr-Ameli
Verily in this is a sign, yet most of them do not believe
Al-muntakhab fi tafsir al-Qur'an al-Karim
This is indeed emblematic of Allah's Omnipotence and Authority but most of them denied Allah, the Creator.(to Pharaoh' people Allah was the Pharaoh himself)