Why did the revelation descend upon the Prophet (peace and blessings be upon him) when he was 40 years old?

Revelation descended upon the Prophet, peace and blessings be upon him, when he was forty years old. This is agreed upon by scholars of sira (prophetic biography) and history, and it is indicated by the Almighty’s saying: {Indeed, I have remained among you for a lifetime before it} [Yunus: 16]. Al-Mubarakpuri specified the day of the revelation's descent as Monday, the twenty-first night of Ramadan, corresponding to August 10, 610 CE. The wisdom behind the revelation descending at the age of forty is that it is a stage of maturity, intellectual perfection, and the acquisition of experience.