"And We had certainly given the Children of Israel the Scripture," meaning: We revealed it to them. "And authority," Qatada said: He means wisdom, which is the Sunnah. "And We provided them with good things," meaning what was made lawful for them. "And We preferred them over the worlds," meaning: the worlds of their time. "And they did not differ except after knowledge had come to them - out of jealous animosity among themselves." They desired the worldly life and its comfort, so they altered their Scripture, making lawful within it what they wished and prohibiting what they wished, and they assumed leadership over the people to exploit them for their sustenance.