All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Know that it is not a condition that the Quran should contain a detailed description for every Islamic issue or instruction; otherwise, the Quran would to be in so many volumes and no one could read it or memorize it. So, Allah, The Great and Almighty, has mentioned only the comprehensive issues, general rules and concise rulings, and then, granted the Prophet the authority to expound and state the above-mentioned generalization. He, The Great and Almighty, has also made following the Sunnah of the Prophet an obligation for every Muslim.
Allah Says (what means): {And whatever the Messenger has given you - take; and what he has forbidden you - refrain from.} [Quran 59:7]
Thus, it becomes clear that it is a duty to follow the Prophetic Sunnah, since such a matter is a Divine Order. Moreover, the Sunnah is related to the Quran and both the Quran and the Sunnah are two forms of Divine Inspiration. Thus, scholars make no difference between the Quran and the Sunnah concerning taking them as a source of evidence and proof while making judgments.
Allah Says (what means):
• {Nor does he speak from [his own] inclination. It is not but a revelation revealed.} [Quran 53:3-4]
• {And We revealed to you the message that you may make clear to the people what was sent down to them and that they might give thought.} [Quran 16:44]
• {And Allah has revealed to you the Book and wisdom and has taught you that which you did not know.} [Quran 4:113]
The word wisdom (mentioned above) means the Sunnah of the Prophet .
As a final word, there is no objection if you do not find detailed rulings of Prayer in the Quran, since such a matter is included in the Divine Order to follow the Messenger .
For more benefit that it is compulsory to abide by the Sunnah and that it is like the Quran in legislation, please refer to Fataawa 92485, 91740 and 88197.
Allah knows best.