Deuteronomy 30:20 in the King James Version
That thou mayest love the LORD thy God, and that thou mayest obey his voice, and that thou mayest cleave unto him: for he is thy life, and the length of thy days: that thou mayest dwell in the land which the LORD sware unto thy fathers, to Abraham, to Isaac, and to Jacob, to give them.
Context
19 I call heaven and earth to witness against you today that I have set before you life and death, the blessing and the curse. Therefore choose life, that you may live, you and your descendants,
20 to love the LORD your God, to obey his voice, and to cling to him; for he is your life, and the length of your days, that you may dwell in the land which the LORD swore to your fathers, to Abraham, to Isaac, and to Jacob, to give them.