What is the ruling on attributing the founding of Sharia (religions) to the Messengers? Is this considered polytheism and exaggeration, or is it permissible?

The Sharia is what Allah Almighty has legislated through His prophets. Allah is the true Legislator, and the Messenger, peace and blessings be upon him, conveys His legislation. The Messenger has the right to legislate independently, but he is infallible in conveying the message and legislates only what Allah wills. The statement that the Messenger is the founder of the Sharia and religion is incorrect, as legislation is attributed to Allah Almighty. The terms "Shari'" (legislator) or "Musharri'" (legislator) are not used for human beings in the language of Islamic jurisprudence; rather, legislation is attributed to Allah Almighty, as in His saying: "He has ordained for you of religion what He enjoined upon Noah."