8:35 Salah Before Islam
This tells the innovation and digression they has introduced to Salah, as they did with Hajj, they took off their cloth and came out from the back of their houses. Hajj we know even from Quran that it was announced by Araham. There too we find that God asks Abraham and Ishmael to purify His house for those who do Ruku’ and Sajda’ which refer to Salah. Referring Salah without any details or reference itself an evidence that audience knew what Salah is and God is criticizing their wrong practices.