כי יפליא, he will separate himself from all the vanities and physical pleasures in life.

לנדור נדר נזיר, to become a Nazirite and the life of self denial which comes with this.

'להזיר לה, to separate himself from all the pleasures in order to devote himself exclusively to the service of the Lord, to study His Torah and practice walking in His ways.

מיין ושכר יזיר, he is not to flagellate himself, or practice fasting, but only to abstain from wine and intoxicating liquids. The former methods of self-denial would result in a diminished ability to serve the Lord with all one’s faculties. Flagellation, a common practice among certain types of monks and “holy men,” is not allowed, but becoming a teetotaler does reduce the urge to let oneself go and engage in demeaning activities due to drunkenness

תער לא יעבור על ראשו, by not coiffing his hair through trimming it to certain shapes, he automatically abandons all manner of preening himself.

קדוש יהיה, separate from base urges and addiction to the pleasures of the flesh.

על נפש מת לא יבא; he must not desecrate his sacred activities by honouring the dead and thereby downgrading his spiritual concerns. In this respect he is much like the High Priest. Our sages report that a father who had sent his son to study Torah in an advanced academy in Tiberias heard that his son was engaged in doing charitable deeds there. When the father heard about it he sent the following message to his son: “are there no opportunities to perform such charitable deeds in our town that I had to send you to Tiberias to do this?” (Jerusalem Talmud Chagigah 1,7) The point is that there are other people who can perform the charitable deed of burying the dead so that the services of the Nazirite are not required.

'קדוש הוא לה. He will merit the light available for those enjoying eternal life, as well as be able to instruct the spiritual leaders of his generation. This may have been what Elkanah referred to when he said: “may the Lord keep His word” (Samuel I 1,23). What he meant was that he agreed with Chanah his wife’s vow that the child she would bear would spend his life on earth as a Nazirite. He did not add any additional request regarding the child that would be born to them. If G’d would allow Chanah’s prayer and vow to come true this would be more than enough satisfaction for him.

יביא אותו, our sages in B’rachot 8 have already explained this to mean that the Nazirite is to bring himself, as it were. Normally, when someone is being prepared for a higher status than that he had attained in the past, such a person is being “brought” to his new assignment by someone superior to himself. This is why the person afflicted with tzoraat is brought to the Temple. Here. the Nazir presents himself in the Temple instead of being brought, i.e. presented by someone superior. Compare Leviticus 14,2 concerning the צרוע, and concerning the Sotah where the Torah had also written in Numbers 5,15 that the husband was to bring his wife to the priest. Similarly, a Jewish servant, asking to extend his term of service beyond the original 6 years, is brought to the door post to have his ear pierced by his master. (Exodus 21,6). Contrary to all this, the Nazirite at the end of his term who will once more begin to shave the hairs of his face and head, thus becoming “a new man,” brings himself. The reason is simple. There is no one on a higher spiritual niveau who could act as the one “bringing” him, i.e. presenting him.

יברכך, with material wealth. The reason this is the first of the blessing is explained by our sages in Avot 3,17 אם אין קמח אין תורה, “if there is no flour, (no economic base) a Torah environment cannot flourish.”

וישמרך, and protect you from those who steal material possessions.

יאר, may He grant light to your eyes to see and appreciate all the wonderful things G’d has done and keeps on doing. You should become aware that all that you achieve is due to His blessing.

ישא ה' פניו אליך, giving you a vista of the world to come which awaits you. The line is similar in essence to what David said in Psalms 36,10 כי עמך מקור חיים באורך נראה אור, “with You is the fountain of life; by Your light do we see light.” It also reflects the statement of our sages in B’rachot 17 that in the world of the future the righteous sit with their crowned heads and enjoy the radiations of G’d’s glory.

וישם לך שלום, the serenity of peace which is equivalent to an infinite, unbroken and undisturbed existence, not tainted by punishment, something which is a feature of life in the world to come.