It is called Islamic Shari'a in Arabic
Quran is God revelation and His words to prophet Muhammad through the Angel Gabriel. Hadith is prophet Muhammad saying.
The Quran and hadith
No it does not say in the quran or any hadith
Hadith
rephrase
In Islamic teachings, the Quran is considered the holy book revealed by God to Prophet Muhammad, while hadith are the sayings and actions of Prophet Muhammad. Hadith are used to provide context and explanation for the teachings in the Quran, helping Muslims understand and apply the principles and laws outlined in the Quran.
their main book is Quran. also Nahj al-Balaghe (collection of sayings of Imam Ali)- brother of Quran and Sahifeh Sajadieh (worships from Imam Sajad)- Sister of Quran also 4 main Hadith book that contains near 120,000 Hadith from the fourteen infallibles.
The holy Quran & the Hadith are the first main sources of legislations in Islam,respectively.
The Quran was revealed in Arabic to the Prophet (peace be upon him) who was also an Arab. The sayings and teachings of the Prophet (peace be upon him) which explain the Quran and taught the how to live their life by the Quran are called hadith and are also in arabic.
The Prophet Muhammad (Peace be upon him) was described by his noble wife, 'Aa'ishah (May Allah be pleased with her)as a "walking Quran": in other words, he didn't just read and recite the Quran, he lived it.
The Quran is considered the ultimate authority in Islam, as it is believed to be the literal word of God. Hadith, on the other hand, are the teachings and actions of the Prophet Muhammad and are considered secondary to the Quran in terms of authority. While the Quran is seen as infallible and unchangeable, hadith can vary in authenticity and interpretation.
One should study hadith because of good guide line which did not cover in Quran.