What is the evidence that rulings mentioned in hadiths are obligatory, and what are some examples of obligations not mentioned in the Qur'an but found in hadiths?

The Prophetic Sunnah is an independent source of legislation, and it independently legislates rulings such as prohibition and obligation. Many rulings were not mentioned in the Holy Quran. Among what the Sunnah has mandated are: reciting Al-Fatihah in prayer, maintaining tranquility during it, commencing the prayer with takbir (pronouncing Allahu Akbar), concluding it with taslim (saying As-salamu alaykum), and mourning for a widow during her waiting period (iddah). The Prophet, peace and blessings be upon him, said: "Indeed, I have been given the Quran and something similar to it along with it." Scholars have given examples of this, such as the prohibition of the meat of domestic donkeys, and every beast of prey with fangs, and every bird of prey with talons.