Why did the Messenger, may Allah bless him and grant him peace, choose the month of Ramadan for worship?

Allah has singled out the month of Ramadan (definition) for worship and fasting according to His wisdom and will, which humans do not know with certainty. Indeed, He, the Almighty, has preferred some times, places, and creatures over others. This is a testament to His immense glory and dominion, and evidence of His perfect power and wisdom. Ibn al-Qayyim explained that Allah chose the purest of creations and singled them out for Himself, and among these is His preference for the month of Ramadan. As for the Prophet, peace be upon him, singling out Ramadan for worship after prophethood, this was by revelation from Allah. As for his devotion therein before prophethood, we do not know its details, and it might have been from the remnants of the religion of Abraham, peace be upon him.