I think what he means is that just like the ka'aba remained since Abraham and the Tawaf and the safa and marwa, the pagans also had the prayer ritual. This is the view of some of the Quranist. There are also Quranist who say the rituals came to us from common practice passed down and not from oral hadith with a few people and therefore they trust them more. Imam Shafi even said that the 5 prayer ritual and haj were common to the public and everybody knew them and never questioned them. So there rituals like Jum'a prayer and eid prayer and tawaf and stoning the devil in haj and the salat perfromance are all passed down from common practice and there is no hadith that teaches us that so some Quranist follow that. But many Quranist believe this is against the Quranic injunction since the Quran says:
The only salat mentioned by name is Fajr and Isha and the other salat mentioned is salat al-wusta.
24.58 O ye who believe! let those whom your right hands possess, and the (children) among you who have not come of age ask your permission (before they come to your presence),** on three occasions: before morning prayer(Salat fajr);** the while ye doff your clothes for the noonday heat; and after the late-night prayer(Salat Isha): these are your three times of undress: outside those times it is not wrong for you or for them to move about attending to each other: Thus does Allah make clear the Signs to you: for Allah is full of knowledge and wisdom.
"You shall consistently observe the salat, especially the MIDDLE PRAYER(Salat Al-Wusta), and devote yourselves totally to God." (2:238).
The only place in the Quran the timimgs of the salat is talked about is in two verses 17.78 and 11.114.
"You shall observe the salat prayer when the sun goes down until the darkness of the night. You shall also observe the Quran at dawn. Reading the Quran at dawn is witnessed." (17:78).
"You shall observe the salat prayers at both ends of the daylight, and during the adjacent hours of the night. . . " (11:114)
These are the verses that types of prayers are actually mentioned by name. And these are the verses where the timings of the salat is mentioned. there are no other verses in the Quran other than the ones above.
The only timings or numbers of salat mentioned in the Torah or Gospel is found in the Torah with Daniel and David
Now when Daniel learned that the decree had been published, he went home to his upstairs room where the windows opened toward Jerusalem. Three times a day he got down on his knees and prayed, giving thanks to his God, just as he had done before, (Daniel 6:10)
16 **As for me, I will call upon God; and the LORD shall save me. ** 17 Evening, and morning, and at noon, will I pray, and cry aloud: and he shall hear my voice. (Psalm of David 55)
Thats all there is in the Quran and previous scriptures and none of them has a specific way to pray
**Some Quranist who pray the Sunni way but have a problem with tashahud, they believe this practice was passed down in its current form from Abraham and Ishamel, while other simply pray according to their interpretation of the Quran and pray two or three and believe as long as you stand or prostrate and bow or kneel then you are praying, they believe in no way specific ritual for praying. Other simply pray like Sunnis do since they follow the practiced Sunnah . **
Nowhere in the Quran is the "5 salat" ever mentioned.
I hope this answered your question.
"You shall observe the salat prayer when the sun goes down until the darkness of the night. You shall also observe the Quran at dawn. Reading the Quran at dawn is witnessed." (17:78).
But at what time and how??????
"You shall observe the salat prayers at both ends of the daylight, and during the adjacent hours of the night. . . " (11:114)
At what time and how????????????