Is dyeing the hair black permissible or forbidden, and if forbidden, what is the reason for its prohibition?

Dyeing hair black is forbidden for anyone other than a mujahid (one who strives in the path of Allah), due to the Prophet's (peace be upon him) prohibition of it. Some scholars have explained this by stating it prevents arrogance and pride, encourages the soul to obedience, and reminds one of the Hereafter. It is also narrated that the first to dye his hair black was Pharaoh, and opposing tyrants is an intended aim of the Sharia. As for the recommendation to change grey hair with a color other than black, it achieves two benefits: cleaning the hair and opposing the People of the Book.