The Lord said to Moses, Tell Aaron and his sons,
‘This is how you are to bless the Israelites. Say to them:‘The Lord bless you and keep you; the Lord make his face shine on you and be gracious to you; the Lord turn his face toward you and give you peace.' “So they will put my name on the Israelites, and I will bless them.
This blessing has been used by both Jews and Christians in their worship. It acknowledges that it is God who gives all good things, and particularly asks for the gift of God's peace.
Why?
The Lord bless you and keep you: Only God has authority may blesses you and keep your safety.
The Lord make his face shine on you and be gracious to you: then God is rejoice with us and we need the grace from the Lord.
When God turn his face toward us will give us peace. For we are children of the Lord.
May I be the blessing of the Lord to others.
In Chinese Bible it is
願耶和華賜福給你,保護你。願耶和華使他的臉光照你,賜恩給你。願耶和華向你仰臉,賜你平安。
How?
So I am a witness and I may bless other with this words.