The Eternal bless thee, and keep thee; As befits its poetic nature, reams of commentary have been written on this blessing. Don't worry I'm not planning a comprehensive review, not even of the interpretations I like, just a few that seem fitting for Leah and Benyamin to take with them on their way.
The Eternal make His face to shine upon thee, and be gracious unto thee;
The Eternal lift up His countenance upon thee, and give thee peace. (Numbers 6:23-26)
Many commentators ask why “keep you” is necessary after “bless you?” If a person is blessed by God, what more does he or she need? Isn’t the additional protection superfluous. No, it is not. In the words of Rabbi Naphtali Tzvi Yehuda Berlin (1816-1893, Russia and Poland), “Everyone receives the blessing appropriate to their circumstances, knowledge to the student or success in commerce to the businessperson, etc. and everyone needs protection so that the blessing does not become an obstacle, leading to excessive pride or improper use.”
There are many interpretations of the word translated here as “be gracious unto thee.” One opinion in Numbers Rabbah (date of compilation disputed, 9th-12th century) connects it to the fourth paragraph in the weekday Amida prayer where the same root appears in “You graciously grant humans knowledge and teach understanding to mortals” making the blessing a prayer for knowledge and understanding while another comprehends the word as a mutual form and specifies the content of that knowledge, “Give them the knowledge to be gracious unto each other.” According to this interpretation the blessing is more prescriptive than promissory. Perhaps the verse as a whole means that God’s face will shine on those who are gracious to each other.
In his commentary on the third verse, Rabbi Isaac Arama (c. 1420-1494, Spain) stresses that “peace” is not merely the absence of argument and contention but “the essential, common good that joins people together.”
Taken together, we have the elements that combine to form the good times that are the backbone of a healthy marriage: appropriate blessings and the wisdom to use them properly, mutual respect and peace that is more than the absence of argument but rather extends to an all-encompassing, common good.
Leah and Benyamin, may you have many years together and may you learn to draw strength and blessing from each other and from the peak experiences you share so you can traverse the other stuff in peace.