What is the wisdom behind the Prophet's polygyny and his marriage to Aisha when she was nine years old, and was his marriage by divine revelation from Allah?

The Prophet, peace and blessings be upon him, married Zaynab by divine revelation. Allah Almighty says: "So when Zayd had completed his aim with her (divorcing her), We gave her to you in marriage, so that there may be no difficulty for the believers concerning the wives of their adopted sons, when they have completed their aim with them. And Allah's command is always accomplished." He married Aisha by divine guidance, as he saw in a dream a girl in a silk garment. He uncovered her, and behold, it was Aisha. He said: "If this is from Allah, He will make it come true." There are no texts indicating that his marriages to his other wives were by specific divine revelation.