Albert Barnes Commentary Isaiah 38:19

"The living, the living, he shall praise thee, as I do this day: The father to the children shall make known thy truth." — Isaiah 38:19 (ASV)

The living, the living - An emphatic or intensive form of expression, as in Isaiah 38:11, Isaiah 38:17. Nothing would express his idea but a repetition of the word, as if the heart was full of it.

The father to the children - One generation of the living to another. The father shall have so deep a sense of the goodness of God that he shall desire to make it known to his children, and to perpetuate the memory of it in the earth.