What is the meaning of "Yehi Shmo l'Olam Lifnei Shemesh Yinun Shmo"?
Pesachim 54a: Mashi'ach's name existed before the world was created.
Sanhedrin 98b: Mashi'ach's name will be Yinun.
Rashi: Shlomo's name will always be mentioned for his wealth and Chachmah; it will be aggrandized all the days of the sun. Yinun is an expression of authority, like "v'Achariso Yihyeh Manon" (Mishlei 29:21). "Ul'Nini" (Bereishis 21:23) is the one who will have authority over my property after me. Radak - just like a son is a remembrance of his father, so his name will be a permanent remembrance of the good deeds that he will do.
Malbim: He will be very famous. His name will go from grandson to grandson, for generations, in front of the sun's trajectory. Just like the sun goes around, illuminates and dispels physical darkness, so his name will go around, illuminate and dispel darkness of Nefashos.
How will they be blessed in him?
Rashi: One will say to his son 'you should be a Chacham and wealthy like Shlomo.'
Radak: This is like "v'Hisbarachu b'Zar'acha Kol Goyei ha'Aretz" (Bereishis 22:18). People will say, Hashem should bless you, like He blessed Ploni.
What is the meaning of "Ye'ashruhu"?
Radak: They will say that he is fortunate.
Malbim: They will consider him to be the [ultimate] happiness of the Nefesh, to the point that they will intend the happiness of their Nefesh corresponding to his ways and deeds.
