In it, we find the priestly blessing:.
Speak to Aaron and to his sons, saying so shall you bless the Children of Israel, say to them: May the Lord bless you and keep you; May the Lord shine His countenance upon you and may He be gracious to you; May the Lord lift His countenance to you and bring you peace. They shall place My name upon the Children of Israel and I shall bless them.
Lord Rabbi Jonathan Sacks wrote:
This is among the oldest of all prayer texts. It was used by the priests in the Temple. It is said today by the cohanim in the reader’s repetition of the Amidah, in Israel every day, in most of the Diaspora only on festivals. It is used by parents as they bless their children on Friday night. It is often said to the bride and groom under the chuppah. It is the simplest and most beautiful of all blessings.
Click here for an article on Kveller with a thoughtful perspective on blessing our children.