Why did God tell Moses that Abraham, Isaac and Jacob did not know the name "Jehovah" in Exodus 6:3 when we can see that Abraham called a certain place place "Jehovah Jireh" in Genesis 22:14?
Because God did not reveal His Name until Moses asked Him to in Exodus 3:14. I AM THAT I AM - I am all that you need. The Genesis reference is in the story...