'Chosen People' doesn't even mean anything. God chose the Israelites (Bloodline of Jacob, not the Askenaz) for certain missions because they were loyal to God. Ironically God kept punishing the Israelites because they were ungrateful and doubtful even after God performed so many miracles for them like parting the Red Sea, obliterating the Egyptians, and much more. God trolled Israelites through Moses for a while giving them so many laws (10 commandments) that they were doomed to fail. Then Moses plead with God not to destroy his people because of the covenant made to Abraham, Jacob, and Isaac that their offspring would be fruitful and given great nations. So God remembered, and gave Moses the schematic to build the Ark of the Covenant which Aaron (Moses' brother) and his priests would perform blessings to forgive his people of the sin they committed to somewhat nullify a lot of the 10 commandments.
Exodus is a harsh read tbh. The lesson in that book is to be Grateful.