New Defender's Study Bible Notes
4:24 kill him. According to the Abrahamic covenant (Genesis 17:10-14), neglect of the rite of circumcision was a capital crime for an Israelite. Moses had failed to appreciate its great importance in God’s sight, but this action of Zipporah satisfied God’s demand that His laws be obeyed.
4:31 the people believed. Initially the Israelites accepted Aaron at his word. However, their attitude soon changed as evidenced by Exodus 6:9.