What is the basis upon which the 2.5% rate for Zakat was determined, and who determined this rate?

The amount of Zakat on gold, silver, and currency is a quarter of a tenth (2.5%). This amount has been established by authentic hadiths from the Prophet, peace be upon him, such as the hadith of Ibn Umar and Aisha regarding the Zakat on dinars, and the hadith of Ali and Anas regarding the Zakat on silver. There is no disagreement among scholars regarding this amount. As for the wisdom behind this determination, the fundamental principle is that a Muslim acts according to what the Sharia has brought forth, whether he comprehends the wisdom or not. There is no impediment to seeking wisdom, but what is prohibited is ceasing to act upon the legislation or doubting it due to not comprehending the wisdom. As long as the Sharia has specified this percentage, it is the most appropriate for the condition of both the Zakat payer and the recipient.