The name Lo-ammi delivers the harshest judgment because it suggests the end of Israel's covenant with the Lord. The title "my people," given to Israel when they obeyed the Lord their God (Leviticus 26:12; see also Exodus 6:7), was now taken away due to their clear unfaithfulness.
I am not your God: The Hebrew phrase can be translated as I am not ‘I Am’ for you (compare Exodus 3:14). The third child's name prophetically states that the Israelites are outside the covenant and can no longer call upon the I Am.