Deuteronomy 11:21 KJV
That your days may be multiplied, and the days of your children, in the land which the Lord sware unto your fathers to give them, as the days of heaven upon the earth.
Deuteronomy 11:21, King James Version
In context
20 And thou shalt write them upon the door posts of thine house, and upon thy gates:
21 That your days may be multiplied, and the days of your children, in the land which the Lord sware unto your fathers to give them, as the days of heaven upon the earth.
22 For if ye shall diligently keep all these commandments which I command you, to do them, to love the Lord your God, to walk in all his ways, and to cleave unto him;