How Hazrat Amr bin Al-As Radhiyallahu Anhu was aware of the Quran's Miracle due to Surah Asr

They have mentioned that Hazrat Amr bin Al-As Radhiyallahu Anhu went to visit Musaylamah Al-Kazzab after the Messenger of Allah Sallallahu Alaihi Wasalam was commisioned(as a Prophet)and before Hazrat Amr Radhiyallahu Anhu had accepted Islam.Upon his arrival,Musaylamah said to him:"What has been revealed to your friend(Muhammad)during this time?".Hazrat Amr Radhiyallahu Anhu said:"A short and concise Surah has been revealed to him".Musaylamah then said:"What is it?".Hazrat Amr Radhiyallahu Anhu replied:"(By Al-Asr.Verily,man is loss.Except those who believe and do righteous deeds,and recommend one another to the truth,and recommend one another to patience)".So Musaylamah thought for a while.Then he said:"Indeed something similar has also been revealed to me".Hazrat Amr Radhiyallahu Anhu asked him:"What is it?".He replied:"Oh Wabr(a small,furry mammal;hyrax),Oh Wabr!You are only have two ears and a chest,and the rest of you is digging and burrowing".Then he said:"What do you think,Oh Amr?".So Hazrat Amr Radhiyallahu Anhu said to him:"By Allah!Verily,you know that I know you are lying".
I saw that Abu Bakr Al-Khara'iti Rahimahullah mentioned a chain of narration for part of this story,or what was close to its meaning,in volume two of his famous book Masawi' ul-Akhlaq.The Wabr is a small animal that resembles a cat,and the largest thing on it is its eard and its torso,while the rest of it is ugly.Musaylamah intended by the composition of these nonsensical verses to produce something which would oppose the Quran.Yet,it was not even convicing to the idol worshipper of that time.Imam At-Tabrani Rahimahullah recorded from Abdullah bin Hisn Abi Madinah Rahimahullah that he said:"Whenever two men from the Companions of the Messenger of Allah Sallallahu Alaihi Wasalam used to meet,they would not part until  one of them had recited Surah Al-Asr in its entirety to the other,and one of them had given the greetings of peace to the other".Imam As-Shafie Rahimahullah said:"If the people were to ponder on this Surah,it would be sufficient for them"(Ibnu Kathir)