In the Old Testament, the Egyptian ruler during the period of Prophet Ibrahim (as) and Prophet Yusuf (as) are named "Pharaoh." However, this title was actually employed after the eras in which these two Prophets lived.
While addressing the Egyptian ruler at the time of Prophet Yusuf (as), the word "Al-Malik" in Arabic is used in the Qur'an: It refers to a ruler, king or sultan:
The King said, 'Bring him to me straight away!'… (Qur'an, 12:50)
The ruler of Egypt in the time of the Prophet Musa (as) is referred to as "Pharaoh." This distinction in the Qur'an is not made in the Old and New Testaments nor by Jewish historians. In the Bible, the word "Pharaoh" is used, in every reference to an Egyptian monarch. On the other hand, the Qur'an is far more concise and accurate in the terminology it employs.
The use of the word "Pharaoh" in Egyptian history belongs only to the late period. This particular title began to be employed in the 14th century B.C., during the reign of Amenhotep IV. The Prophet Yusuf (as) lived at least 200 years before that time.216
The Encyclopaedia Britannica says that the word "Pharaoh" was a title of respect used from the New Kingdom (beginning with the 18th dynasty; B.C. 1539-1292) until the 22nd dynasty (B.C. 945-730), after which this term of address became the title of the king. Further information on this subject comes from the Academic American Encyclopaedia, which states that the title of Pharaoh began to be used in the New Kingdom.
In this way We give you news of what has gone before and We have given you a reminder direct from Us. Those who turn away from it will bear a heavy burden on the Day of Rising.
(Qur’an, 20: 99-100)
As we have seen, the use of the word "Pharaoh" dates from a specific period in history. For that reason, the fact that the Qur'an distinguishes between the different Egyptian titles in different Egyptian eras is yet another proof that the Qur'an is Allah's Word.
216. Elias Karîm, “Qur’anic Accuracy vs. Biblical Error: The Kings & Pharaohs of Egypt,” www.islamic-awareness.org/Quran/Contrad/External/josephdetail.html; Dr. Abu Ameenah Bilal Philips, “An Aspect of the Qur’aan’s Miraculous Nature,” www.islaam.com/Article.asp?id=40.