לבנימין אמר, "to Binyamin he said:" according to the plain meaning of the text the preposition ל here must be understood as בעבור, "for the sake of, on behalf of;⁠" Moses means that seeing Binyamin is a favourite of the Lord, He will make His residence (Temple) in the territory of that tribe. The tribe will dwell in security, trusting the Lord, the Lord His God dwelling between his shoulders.

חופף עליו, "it hovers over him;⁠" a reference to God's attribute of כבוד, i.e. the Shechinah which rested over Jerusalem, most of which was situated in the territory of Binyamin. The reason Moses speaks of the Shechinah hovering between the shoulders of Binyamin instead of "over his head,⁠" is because the floor of the courtyard to the Temple the עזרה did not literally stand on the top of the mountain but about 23 cubits below the summit, near the level of a well called Eytam (Yoma 31). It had been David's intention to build it there as explained in the Talmud Zevachim 54. Moses refers to the Temple here as "shoulder,⁠" and so did Joshua his disciple in Joshua 16,5. The reason Joshua added the word "Jebusite" there is to hint that David purchased the site from Arona the Jebusite (Samuel II 24,24).
Some (Ibn Ezra) explain the words: "between his shoulders" as describing the fact that the Temple stood in the middle of the tribal territory of Binyamin.

A Midrashic approach: our verse contains allusions to three Temples. (compare Zevachim 118) The words ישכון לבטח, "will dwell safely,⁠" refer to the first Temple, Solomon's. This is why in the Book of Chronicles the attribute כבוד is specifically mentioned as filling the inside of that Temple (Chronicles II 7,1). The words "He (the attribute כבוד) hovers over it all day long,⁠" refer to the second Temple; the word "hover" denotes a less regular presence than does the word ישכון used by Moses as describing the situation during the first Temple. Finally, the words: "and He dwells between his shoulders,⁠" are a reference to the third Temple when the full extent of the Shechinah will return to the Holy of Holies. This is what our sages explained in Sifri on our verse.
The reason all these allusions are contained in the blessing for Binyamin is that it was this tribe which served as host for the Divine presence. We have a tradition that the body of the original Binyamin was never attacked by worms. There are seven people concerning whom we have a tradition that their bodies were not attacked by worms. They are: Avraham, Yitzchak, Yaakov, Moses, Aaron, Miriam and Binyamin the son of Yaakov (compare Baba Batra 17). Of Avraham, Yitzchak, and Yaakov the Torah said specifically that God blessed them in all respects, i.e. בכל, מכל, כל respectively. Of Moses and Aaron the Torah writes that they died על פי ה', If they died "by a kiss" as our sages describe their mode of dying, it is reasonable that God would not allow the worms to attack their remains. Although the Torah, for obvious reasons, does not describe Miriam's death as similar to that of her brothers, our sages feel certain that her death was similar. As to Binyamin's death, the very description of him as ידיד ה', "beloved of the Lord,⁠" surely suggests a similar treatment of his body by the Lord. Some sages say that David's body too was not attacked by worms. They base this on Psalms 16,9 ("also my flesh will dwell securely"). I have heard a support for this theory from Exodus 16,24 describing that the manna which fell on Fridays did not turn putrid and was not attacked by worms, contrary to the manna which fell on other days and was saved overnight. The word הבאיש, normally understood as "turned putrid,⁠" could be read with the first two letters as an acrostic so that it would be ה'ב איש, meaning "7 men" (were not attacked by worms), etc. This would serve as Scriptural support for the view of Rabbi Eleazar that Miriam was also one of the people whose flesh was not attacked by worms. (to make up the number ה'ב=7) The word בו in that same verse in Exodus, having a numerical value of 8, would serve as support for the view that the flesh of an eighth' person was immune to worms, i.e. the flesh of David.

A kabbalistic approach: The words: לבנימין אמר ידיד ה' ישכון refer to the attribute כבוד having made this statement. As a result of that attribute dwelling among the tribe of Binyamin, the latter felt secure, i.e. לבטח, being confident that he was under the protection of God, the Essence. The whole matter is similar to what we read in Exodus 14,31: וירא ישראל את היד הגדולה ויאמינו בה', "as soon as Israel saw the 'great' hand, they believed in the Lord.⁠" This is also the reason that the prophet Nathan named David's second son from Bat Sheva ידיד-יה (Samuel II 12,25) ["beloved one of God,⁠" to show publicly that no stigma was attached to the union of David and Bat Sheva now. Ed.]

According to the Sefer HaBahir item 65, God said to Solomon: "seeing you bear My name, I will allow you to be the one to build the Temple for Me.⁠" This is the meaning of Kings I 5,26: "and the Lord had given [I believe the key is the word נתן instead of ויתן, which would have meant that this wisdom had been granted to Solomon only at that point. Ed.] wisdom to Solomon, as He said to him.⁠" We do not have a verse (at that junction) where God is on record as granting wisdom to Solomon. However, in Kings I 3,28 we have this verse: "when all of Israel heard the decision of the king (about the two women who each claimed that the baby was hers) they stood in awe of the king; for they saw that he possessed divine wisdom to execute justice.⁠" Thus far the Sefer HaBahir. [the author of that book also refers to the sages who said that every time the word שלמה appears in Song of Songs we must treat it as one of the holy names of God.
From all the foregoing we learn that among all the tribes there was none who was as blessed as Binyamin in that the Shechinah dwelled among him permanently in a more concentrated form than among any of the other tribes. Clearly, he possessed greater merit than the other tribes. Perhaps this is also the reason why this tribe was singled out to be mentioned separately, i.e. Moses begins his blessing with the word לבנימין, instead of ולבנימין, which would have emphasized what he had in common with the tribes mentioned first. (Only Reuven, who was mentioned first, did not have the letter ו meaning "and" introducing him). Perhaps, just as the etrog occupies a special position among the four species, not being tied up together with the other three species, the absence of the letter ו when introducing the blessing for the tribe of Binyamin may convey similar considerations. The absence of the letter ו (where we really would have expected it) may be a hint that Binyamin is to be perceived as part of the בנין, "the structure" comprised of the ten sefirot, creative forces, leading to the terrestrial universe.