In these hadiths Muhammad asserts that he and his followers are to follow the religion of their forefather Abraham who supposedly built the Kabah and instituted the rites of pilgrimage. This shows that the Meccans (allegedly) knew and believed that Abraham had traveled there and were therefore aware that Allah had (supposedly) revealed and made known the true religion to their ancestors long before Muhammad was born.
There is more. According to the follow narratives there were pictures of Mary, Abraham and Ishmael in the Kabah:
Narrated Ibn Abbas:
The Prophet entered the Ka'ba and found in it the pictures of (Prophet) Abraham and Mary. On that he said' "What is the matter with them (i.e. Quraish)? They have already heard that angels do not enter a house in which there are pictures; yet this is the picture of Abraham. And why is he depicted as practicing divination by arrows?" (Sahih al-Bukhari, Volume 4, Book 55, Number 570)
Narrated Ibn Abbas:
When Allah's Apostle arrived in Mecca, he refused to enter the Ka'ba while there were idols in it. So he ordered that they be taken out. The pictures of the (Prophets) Abraham and Ishmael, holding arrows of divination in their hands, were carried out. The Prophet said, "May Allah ruin them (i.e. the infidels) for they knew very well that they (i.e. Abraham and Ishmael) never drew lots by these (divination arrows). Then the Prophet entered the Ka'ba and said. "Allahu Akbar" in all its directions and came out and not offer any prayer therein. (Sahih al-Bukhari, Volume 5, Book 59, Number 584)
This shows that the Arabs of Mecca (as well as Medina) knew of and were aware of the Biblical characters such as Abraham and Ishmael. These next hadiths indicate that they also knew that they were (supposedly) descendants of Ishmael and that both he and his mother had (allegedly) settled in Mecca:
Narrated Ibn 'Abbas:
The Prophet said, "May Allah be merciful to the mother of Ishmael! If she had left the water of Zam-Zam (fountain) as it was, (without constructing a basin for keeping the water), (or said, "If she had not taken handfuls of its water"), it would have been a flowing stream. Jurhum (an Arab tribe) came and asked her, 'May we settle at your dwelling?' She said, 'Yes, but you have no right to possess the water.' They agreed." (Sahih al-Bukhari, Volume 3, Book 40, Number 556)
Allah's Apostle passed by some people from the tribe of Aslam practicing archery. He said, "O children of Ishmael! Throw (arrows), for your father was an archer. I am on the side of Bani so-and-so," meaning one of the two teams. The other team stopped throwing, whereupon the Prophet said, "What has happened to them?" They replied, "How shall we throw while you are with Bani so-and-so?" He said, "Throw for I am with all of you." (Sahih al-Bukhari, Volume 4, Book 56, Number 710)
Narrated Abu Huraira:
I have not ceased to like Banu Tamim ever since I heard of three qualities attributed to them by Allah's Apostle (He said): They, out of all my followers, will be the strongest opponent of Ad-Dajjal; 'Aisha had a slave-girl from them, and the Prophet told her to manumit her as she was from the descendants of (the Prophet) Ishmael; and, when their Zakat was brought, the Prophet said, "This is the Zakat of my people." (Sahih al-Bukhari, Volume 5, Book 59, Number 652)
These reports conclusively establish the fact that Allah had already sent revelation to the Meccans and that they were aware of the true religion LONG BEFORE Muhammad was born.