Modern day jews study the teachings of the Talmud. One part of the Talmud is known as "The Oven of Akhnai", which is found in Bava Metzia 59a-b
In this portion of the Talmud, God admits fault and says "My children have defeated me". Basically some Rabbis argue with God and he admits they are right and he is wrong. The text has often been used by jews to indicate Rabbis have more authority than God due to their discernment, and thus, you should follow Rabbinic traditions even if they would seem contrary to what is right.
Using Rabbinic writings to support Rabbinic Authority; and the jews eat it up every time.
The Talmud is not legitimate. Do not trust it.