I am a little rusty on the Bible stories.
Timchochet, what did the Israelites do to become God's chosen people? It is not clear to me whether it is a reward, a punishment or something else.
Per the OT:God promised Abraham that he would be the father of a special people, a chosen nation that would be a blessing to the world. That promise was then continued through his son Isaac and then Isaac's son Jacob. Jacob was then renamed "Israel" and his 12 sons became the 12 tribes of Israel. They multiply in Egypt, become a large group of people, then migrate to modern day Israel.
There is a lot of details going on in between that stuff, but that is the gist.