Sunan al-Shafi'i 388 — The days of Tashreeq

Umar bin Abdul Aziz (may Allah have mercy on him) said that the affairs of the Children of Israel remained correct until children were born to them from slave women of other nations. When (the leadership of religion came into the hands of this generation), they began to make rulings based on their own opinions; they themselves went astray and led others astray as well.