(Psalm 119:50) He will give me live according to his word. He promises this. Life comes through the promise. The promise is in his word. His word is not the promised life, but the vehicle of the promise.
A definition of "according to":
-in agreement with
-consistent with; in conformity with
-on the authority of
-in proportion to
God's promises are contingent to what he actually promises. What he promises is life (Ps. 119:25,50) and he tells us this in his word.