Or HaChaim on Numbers 6:26/אור החיים על במדבר ו׳:כ״ו

1 ישא ה׳ פניו אליך, "May the Lord lift up His countenance upon you, etc." This means that in the event the deeds (sins) of the Israelites have erected some kind of barrier between them and G'd that G'd should lift this barrier and remove it. וישם לך שלום, "and may He grant you peace." The meaning of the word "peace" or "harmony" is the reverse of every kind of separation and fragmentation. Anyone examining the word carefully realises that the concept it represents is the foundation our world is built upon, the force which ensures that the "higher" world and our "lower" world can co-exist successfully. This is the mystical dimension of the words: "and they shall put My name upon the children of Israel," and the concluding words "and I will bless them."