Rashi on the Prophets and Writings

on the first day of the seventh month That is the day of Rosh Hashanah.

from the light of the beginning of the day.
to the Scroll of the Law All the people inclined their ears.

on a wooden tower That wooden tower was made for the purpose of reading the Scroll of the Law upon it.

for he was above all the people Therefore, they all saw him.
and when he opened it, all the people stood And when he opened it to read, all the people stood silent.
stood Heb. עָמְדוּ, an expression of silence (they stood silent), like (Job 32:16): “...for they remained silent (עָמְדוּ) ; they no longer answered.”

with the uplifting of their hands with the raising of their hands, meaning that they lifted their hands on high to thank the Holy One, blessed be He, as it is stated: (I Kings 8:22): “...and spread forth his hands towards heaven.”

explained...to the people meaning that they would translate the words of the Torah to the people.
in their place meaning that they were standing on their feet.

and gave sense Heb. וְשּׂם שֶׂכֶל, and giving wisdom; וְשּׂם is an expression of doing.

The day is holy because it is the day of Rosh Hashanah.
for all the people were weeping because they did not uphold the Torah appropriately.

to whoever has nothing prepared to a poor man who has no food prepared for himself.

quieted They admonished all the people to be quiet, that they should weep no longer.
Hush Heb. הַסוּ, an expression of silence, like (Num. 13:30): “And Caleb hushed (וַיַהַס).”

And on the second day of Rosh Hashanah.

And that they should announce And they commanded that they announce that they celebrate the Festival of Sukkoth, and so it is customary for Scripture to speak in this manner, like (I Sam. 9: 27): “Tell the servant and he will go ahead of us.”
myrtle leaves It is explained in Tractate Succah (12a) that this is a wild myrtle which is unfit for the lulav and only fit to make a sukkah.
date palm leaves for a lulav.
and leaves of plaited trees This is the myrtle that is fit for the lulav as is explained in Tractate Succah (ad loc.).

day by day every day.