Who was the first Jew?

[Daniel2]

At Mount Sinai, the approximately 3 million assembled Israelites entered into a Divine Covenant with G-d and became the Jewish People, and they received the Torah Law from G-d through Moses. From that point on, anyone born to a Jewish mother is a Jew, and is obligated in the Jewish commandments of the Torah. Likewise anyone born to a Gentile mother is a Gentile (one of the Children of Noah), and is obligated in the Noahide commandments of the Torah.

Sh'lom and happy 5770!
Does it say anywhere in the written Torah or the Oral Torah sources that one's biological mother determines whether one is Jewish or a Gentile? I know it's true, but I thought it might be good to know the sources where it says this to prove to others who might question this fact.