In a world of danger, we should help and watch out for others. Also we should observe and assess the situation of the scene if we are able to help or not. Sometimes we can put ourselves in danger too, in that condition we better go out to others for help.
Israel was to keep watch over the vulnerable and care for the needy. Yet they did the opposite—exploiting the people, oppressing the poor. Yet, in the Cain and Abel story, God continued to watch over Cain, even after he was sent away. God did for Cain what Cain should have done for Abel. It’s a beautiful anticipation of what God in Jesus would come to do for us. Jesus keeps us in His care, and He empowers us to go and do likewise for others.