Psalms 41:13

Blessed [be] the LORD God of Israel from everlasting, and to everlasting. Amen, and Amen.

Ver. 13. Blessed be the Lord God of Israel] Thus he sweetly shutteth up this first book of the psalms (as some distinguish) with a pathetic doxology, redoubling his Amen, Fiat, Fiat, to show his fervency, and most earnest desire that God should be blessed by his whole Israel. This was the custom of the Scribes to do, saith Kimchi, when they had finished any book. The other four books of psalms (as they are reckoned) end in like manner.

From everlasting to everlasting] i.e. From the beginning of the world to the end of it; or, as the Chaldee hath it, from this world unto the world to come.

Amen, and Amen] So be it, and so it shall be. Dictio est acclamationis, approbationis, et confirmationis. The Rabbis say, that our amen in the close of our prayers must not be, first, hasty, but with consideration, 1 Corinthians 14:16. Secondly, nor maimed or defective; we must fetch out our hearts after it, and be swallowed up in God. Thirdly, nor alone, or an orphan; that is, without faith, love, and holy confidence. The spirits of the whole prayer are contracted into it, and so should the spirit of him that prayeth.