Why did the noble verse mention only four prayers and not the fifth?

The interpretation of the verse: "So exalted is Allah when you reach the evening and when you reach the morning. And in the afternoon [period] and when you are at noon" is that it encompasses the five daily prayers. Ibn Abbas and the majority of exegetes held that "when you reach the evening" refers to the Maghrib and Isha prayers, "when you reach the morning" refers to Fajr, "in the afternoon [period]" refers to Asr, and "when you are at noon" refers to Dhuhr. Some mentioned that Isha was not mentioned in this verse, but rather in Surah Hud: "and in parts of the night."

Furthermore, the Qur'an mentioned prayer times generally in other verses, such as: "Establish prayer at the decline of the sun until the darkness of the night and [recite] the Qur'an of dawn," and "And establish prayer at the two ends of the day and at the approach of night." The Companions and their successors interpreted these to include the five daily prayers.

Not all legal rulings were mentioned in detail in the Noble Qur'an. The Qur'an mentioned many rulings and indicated the authority of the Prophetic Sunnah, which provided details not found in the Qur'an, for the Sunnah is a revelation from Allah the Almighty.