How did Ibn Abbas memorize the entire Holy Qur’an?

Abdullah ibn Abbas, the scholar of the Ummah and the Imam of Tafsir, was born three years before the Hijrah. The Messenger of Allah, peace and blessings be upon him, supplicated for him, saying: "O Allah, grant him understanding in the religion and teach him interpretation," and "O Allah, teach him the Book," and "O Allah, teach him wisdom." The manner in which he memorized the Qur'an is not mentioned, but he was the interpreter of the Qur'an, and he has a Musnad comprising 1660 hadiths. He passed away in the year 67 or 68 AH, at the age of 71.