In all of the Pentateuch there is only one prescribed prayer given directly by God to man and that is a blessing. In the new Testament there is one prescribed prayer given directly by God to man and that is the Lord’s prayer given by Jesus.

This is the prayer given by God to Moses in numbers chapter 6.

The Lord said to Moses,

“Say to Aaron and his sons,  

Thus you shall bless the sons of Israel you shall say to them.

 The Lord bless you and keep you; the Lord make his face to shine upon you and be gracious to you; the Lord lift up his countenance upon you and give you peace.

So shall I put my name upon the sons of Israel and I will bless them.”

The Nazarite vow taken by Jews was another way of invoking the blessing of God this was usually for 30 days in which the person would not shave or cut the hair, amongst other rules, (cf Num ch6). Both men and women could take this vow and some notable Nazirites are Samuel, Samson, John the Baptist and possibly James. The mother of Samson in return for his birth offered him back to God in a lifelong Nazarite vow.