Midrash su Salmi 92:1

1) (Vayikra 26:6) "and you will lie down and not tremble": without fear of any animal. "and I will eliminate vicious beasts from the land." R. Yehudah says: He will eliminate them from the world. And thus is it written (Tehillim 92:1) "A psalm, a song for the day of Shabbath": for the cessation (mashbith [like "Shabbath"]) of harmful agents from the world. R. Shimon says: He will prevent them from causing harm. R. Shimon said: What redounds more to the praise of the L–rd, the absence of harmful agents or their existing but not causing harm? Certainly, the second.

“Vanity of vanities, said Kohelet; vanity of vanities, everything is vanity” (Ecclesiastes 1:2).
“Vanity of vanities [havel havalim]” – Rabbi Huna said in the name of Rabbi Aḥa: David made a statement and did not explain it, but his son Solomon explained it. Solomon made a statement and did not explain it, but his father David explained it. David said: “Man is like hevel” (Psalms 144:4); to what hevel [is man compared]? If it is to the hevel [heat] of an oven, it has significance. If it is to the hevel of a stove, it has significance. His son Solomon came and explained: “Vanity of vanities [havel havalim], said Kohelet.” Rabbi Shmuel bar Naḥmani taught it in the name of Rabbi Yehoshua ben Korḥa: It is comparable to a person who places seven pots on the fire one atop the other, and the heat of the upper one is insignificant.⁹This comparison is based on the fact that the term vanity [hevel] appears five times in Ecclesiastes 1:2, and twice it appears in the plural, for a total of seven mentions of the term hevel.
Solomon said: “For who knows what is good for man in his life, [all the days of his vain life,] that he spends like a shadow” (Ecclesiastes 6:12). What shadow? If it is like the shadow of a wall, it has substance. If it is like the shadow of a palm tree, it has substance. David came and explained: “His days are like a passing shadow” (Psalms 144:4). Rabbi Huna [said] in the name of Rav Aḥa: Like that bird that passes and its shadow passes with it. Shmuel said: Like the shadow of bees that have no substance at all.
Rabbi Shmuel bar Rav Yitzḥak taught it in the name of Rabbi Shimon ben Elazar: The seven vanities [havalim] that Kohelet mentioned correspond to the seven worlds that a person sees. A one-year-old is like a king who is on a canopied litter and everyone is hugging and kissing him. A two- or three-year-old is like a pig that extends its hands into the sewers. A ten-year-old jumps like a goat. A twenty-year-old whinnies like a horse, beautifies himself and seeks a wife. When he marries a wife he is like a donkey. When he begets children, he is as audacious as a dog to bring [home] bread and food. When he grows old, he is like a monkey. That is stated regarding the common people; however, regarding Torah personalities, it is written: “King David was old” – even though he was old, he was a king.
Rabbi Yehuda ben Rabbi Simon said: The seven vanities that Kohelet mentioned correspond to the seven days of Creation. On the first, “In the beginning God created the heavens and the earth” (Genesis 1:1), and it is written: “For the heavens will vanish like smoke” (Isaiah 51:6). On the second: “Let there be a firmament” (Genesis 1:6), and it is written: “The heavens will be furled like a scroll” (Isaiah 34:4). On the third: “Let the waters be gathered” (Genesis 1:9), and it is written: “The Lord will destroy the tongue of the sea of Egypt” (Isaiah 11:15). On the fourth: “Let there be lights” (Genesis 1:14), and it is written: “The moon will be disgraced” (Isaiah 24:23). On the fifth: “Let the waters swarm [with swarms of living creatures, and let fowl fly above the earth in the open firmament of heaven]” (Genesis 1:20), and it is written: “I will destroy the birds of the heavens” (Zephaniah 1:3). On the sixth: “Let us make man” (Genesis 1:26), and it is written: “I will destroy man and animal” (Zephaniah 1:3). Regarding Shabbat, what do you have to say? “One who profanes it will be put to death” (Exodus 31:14). That is stated regarding one who does so intentionally; but [one who profanes it] unwittingly, he will bring an offering and gain atonement. When Adam saw the praise of Shabbat, that one who brings an offering gains atonement, he began singing in its regard to the Holy One blessed be He, praise and psalm. That is what is written: “A psalm, a song for the day of Shabbat” (Psalms 92:1). Rabbi Levi said: This [psalm] was stated by Adam.

Another matter: “Your hair is like a flock of goats that streams down [shegaleshu] from Mount Gilad” (Song of Songs 4:1) – the mountain from whose midst you took away [shegelashten], I rendered a memorial for the nations of the world. Which is this? These are the priestly watches. What is it that you took away from its midst? “Your teeth are like a flock of ordered ewes” (Song of Songs 4:2) – defined matters, the twenty-four priestly watches, the twenty-four Levite watches, and twelve divisions.⁵⁴These were divisions of men who would come for a month at a time to perform whatever labors the king would assign them (Etz Yosef). “That have come up from bathing” (Song of Songs 4:2) – who protect Israel. “That are all paired” – as we learned there: At three times during the year all the priestly watches were equal (Sukka 55b). “And there is none missing among them” (Song of Songs 4:2) – as we learned: “The first, the head and the hind leg…” (Tamid 31a).⁵⁵Each of the priests had a role, and there were always enough priests to perform each task.
“Your lips are like a scarlet thread” (Song of Songs 4:2) – as we learned: [The High Priest] stooped to pour the libation, and the deputy waved the cloths, and ben Arza struck the cymbals (Tamid 33b).⁵⁶This was the sign for the Levites to begin their song in the Temple. “Your speech is lovely” (Song of Songs 4:2) – this is the song, as we learned there: The song that the Levites would recite in the Temple. On the first day they would recite: “The earth is the Lord’s and all it contains” (Psalms 24:1).⁵⁷The intention is that on Sunday the Levites would recite the entire chapter of Psalms beginning with this verse. The same is true for all of the citations cited here; one psalm was recited each day of the week. On the second day: “Great is the Lord and highly to be praised in the city of God…” (Psalms 48:2). On the third day: “God stands in the divine congregation” (Psalms 82:1). On the fourth day: “Lord God, to whom vengeance belongs, God to whom vengeance belongs, shine forth” (Psalms 94:1). On the fifth day: “Sing for joy to God, our strength; shout aloud to the God of Jacob” (Psalms 81:2). On the sixth day: “The Lord reigns: He is robed in majesty” (Psalms 93:1). On Shabbat they would recite: “A psalm, a song for the Shabbat day” (Psalms 92:1) – for the future, for the day that will be entirely Shabbat and rest for everlasting life.