How valid were the actions of the Prophet Muhammad (peace be upon him) and the application of Sharia in the incident of stoning the two Jewish adulterers? Is the Torah corrupted or not? And why was stoning not mentioned in the Holy Quran? And why did the Prophet not apply the ruling of the Gospel and the New Testament in this incident?

The distortion of Allah's revelation by the People of the Book is a definitive and known fact, as stated in verses of the Holy Quran. This distortion occurred in the Torah, and among its instances was the replacement of the punishment of stoning with blackening the face and lashing. This distortion does not mean that everything in those books is false; rather, they contain remnants of the revelation, such as the continued validity of the ruling of stoning, which the Prophet (peace be upon him) affirmed. The Prophet's knowledge of the Torah's ruling came either through divine revelation or through information from Jews who embraced Islam. As for the punishment of stoning for the married fornicator, it was among what was revealed in the Quran, then its recitation was abrogated while its ruling remained, and the Prophet (peace be upon him) and his successors acted upon it, and scholars reached a consensus on it. The story of Jesus (peace be upon him) with the adulterous woman, mentioned in some Gospels, is doubtful in its authenticity, for Jesus came to confirm the Torah, not to nullify it, and many Gospels do not mention this story.