## Then God spoke to Noah and to his sons with him ##
God was already speaking to them. This phrase marks a change in what God was going to speak about. It can also be translated as "God continued speaking to Noah and his sons" or "Then God went on to say."
## As for me ##
This phrase is used in English to mark the change from God talking about what Noah and his sons must do to talking about what God would do.
## I am going to establish my covenant with you ##
This can be translated as “I will make a solemn promise to you." In this covenant, God made a promise, but he did not require Noah to do anything.