She conceived again, and when she gave birth to a son she said, "This time I will praise the LORD ." So she named him Judah. (Genesis 29:35)
Judah was the fourth son born to Jacob and Leah, and it was from his name that his descendants became known as Jews. Abraham was not a Jew. Isaac was not a Jew. Judah's eleven brothers were not Jews. They were all Israelites, but only Judah's children and descendants, right to this day, are actually qualified to be called Jews. It's more than identifying a correct name, it's a matter of identifying the correct line. And it was in this line that Jesus Christ the savior would be born.
Judah was a kinder man than his brothers, most of whom had decided to kill kid brother Joseph because they were jealous of the attention he got from their father. Judah interposed on behalf of Joseph, so that his life was spared.
Judah said to his brothers, "What will we gain if we kill our brother and cover up his blood? Come, let's sell him to the Ishmaelites and not lay our hands on him; after all, he is our brother, our own flesh and blood." His brothers agreed. (Genesis 37:26-17)
Soon after the sale of Joseph to the Ishmaelites, Judah went to reside at Adullam, where he married a woman of Canaan named Shua. She gave him three sons Er, Onan and Shelah. Judah got a wife for Er, a woman named Tamar, who unfortunately was widowed shortly after they were married. This tale resulted in some rather unpleasant circumstances. [see Tamar]
After Shua died, he returned to his father's house where he exercised much influence over the patriarch, taking a principal part in the events which led to the whole family at length going down into Egypt. We hear nothing more of him till he received his father's blessing.
Judah, your brothers will praise you;
your hand will be on the neck of your enemies;
your father's sons will bow down to you.
You are a lion's cub, O Judah;
you return from the prey, my son.
Like a lion he crouches and lies down,
like a lioness-who dares to rouse him?
The scepter will not depart from Judah,
nor the ruler's staff from between his feet,
until he comes to whom it belongs
and the obedience of the nations is his.
He will tether his donkey to a vine,
his colt to the choicest branch;
he will wash his garments in wine,
his robes in the blood of grapes.
His eyes will be darker than wine,
his teeth whiter than milk. (Genesis 49:8-12).