What are the foundational sources for the legality and establishment of oaths (Yamin)?

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The foundational sources for the legality and establishment of oaths are the Book (Quran), the Sunnah, and the consensus (Ijma). Pertaining to the Book, the evidence includes the saying of Allah: "Allah will not call you to account for what is unintentional in your oaths, but He will call you to account for what you intended by your oaths" (Quran 5:89), and "Do not break your oaths after having affirmed them" (Quran 16:91). Furthermore, the Prophet (peace be upon him) was commanded to swear in three instances: "Say: Yes, by my Lord, it is the truth" (Quran 10:53), "Say: Yes, by my Lord, it will surely come to you" (Quran 34:3), and "Say: Yes, by my Lord, you shall surely be resurrected" (Quran 64:7). Regarding the Sunnah, the evidence is the Prophet's statement: "By Allah, if I take an oath, and then see something else that is better than it, I perform what is better and then release my oath," which is agreed upon (Muttafaqun 'Alayh). The Prophet's most frequent oath was, "O Turner of the hearts and Transformer of the hearts." The Ummah has reached a consensus on the legitimacy of the oath and the establishment of its rulings, using it to confirm what is sworn upon.