Sheikh Saaleh al-Fauzaan, may Allaah preserve him, mentions,
…therefore it is obligatory upon a Muslim to submit to and follow that which comes in those narrations coming from the Messenger of Allaah, may Allaah’s praise and salutations be upon him, because it is the second source of revelation after the Qur’aan. The fundamental sources of evidence in Islaam which the Muslims have
gathered and agreed upon are:
Firstly- the Qur’aan,
Secondly- the Prophet’s Sunnah, and
Thirdly- the Consensus of the people of knowledge.
book: https://taalib.link/methodologiesss preview: https://taalib.link/methodologies