Here are 4 Bible verses about feast of trumpets from the Old and New Testaments of the Holy Bible (King James Version), sorted from most to least relevant.
Nehemiah 8:2-6 KJV
And Ezra the priest brought the law before the congregation both of men and women, and all that could hear with understanding, upon the first day of the seventh month. And he read therein before the street that was before the water gate from the morning until midday, before the men and the women, and those that could understand; and the ears of all the people were attentive unto the book of the law. And Ezra the scribe stood upon a pulpit of wood, which they had made for the purpose; and beside him stood Mattithiah, and Shema, and Anaiah, and Urijah, and Hilkiah, and Maaseiah, on his right hand; and on his left hand, Pedaiah, and Mishael, and Malchiah, and Hashum, and Hashbadana, Zechariah, and Meshullam. And Ezra opened the book in the sight of all the people; (for he was above all the people;) and when he opened it, all the people stood up: And Ezra blessed the LORD, the great God. And all the people answered, Amen, Amen, with lifting up their hands: and they bowed their heads, and worshipped the LORD with their faces to the ground.
Numbers 29:1 KJV
And in the seventh month, on the first day of the month, ye shall have an holy convocation; ye shall do no servile work: it is a day of blowing the trumpets unto you.
Numbers 29:2-5 KJV
And ye shall offer a burnt offering for a sweet savour unto the LORD; one young bullock, one ram, and seven lambs of the first year without blemish: And their meat offering shall be of flour mingled with oil, three tenth deals for a bullock, and two tenth deals for a ram, And one tenth deal for one lamb, throughout the seven lambs: And one kid of the goats for a sin offering, to make an atonement for you:
Leviticus 23:25 KJV
Ye shall do no servile work therein: but ye shall offer an offering made by fire unto the LORD.