Psalms 41:13

Blessed be the Lord God of Israel -That is, Let the Lord God of Israel be praised, honored, adored. The language is an expression of desire that all honor, all happiness, might be His. It is a recognition of God as the source of the mercies referred to, and an expression of the feeling that he is entitled to universal praise. The word Israel here refers to the people of God as descended from Jacob or Israel. From everlasting, and to everlasting -Through eternity, or eternal ages, - from all past duration to all future duration. The expression “from everlasting to everlasting,” would embrace eternity; and the idea is that God is deserving of eternal praise.