Nehemiah 10 & 11 - They took an oath to Keep all of Torah and a curse if they break it. 2004

Neh 10:28
Now the rest of the people, the priests, the Levites, the gatekeepers, the singers, the temple servants, and all those who had separated themselves from the peoples of the lands to the law of God, their wives, their sons and their daughters, all those who had knowledge and understanding,

Neh 10:29
are joining with their kinsmen, their nobles, and are taking on themselves a curse and an oath to walk in God's law, which was given through Moses, God's servant, and to keep and to observe all the commandments of GOD our Lord, and His ordinances and His statutes;

The governor, priests, Levites, and leaders of the people signed the Covenant and represented all the people who had knowledge and understanding in the land to keep this Covenant. They are taking an oath to keep all of Elohim's Torah and taking upon themselves a curse if they break this Covenant. This same type of oath was taken by the people of Israel before they crossed the Jordan into the Land.

Deut. 27:9-26 Then Moses and the Levitical priests spoke to all Israel, saying, “Be silent and listen, O Israel! This day you have become a people for the LORD your God. 10“You shall therefore obey the LORD your God, and do His commandments and His statutes which I command you today.” 11Moses also charged the people on that day, saying, 12“When you cross the Jordan, these shall stand on Mount Gerizim to bless the people: Simeon, Levi, Judah, Issachar, Joseph, and Benjamin. 13“And for the curse, these shall stand on Mount Ebal: Reuben, Gad, Asher, Zebulun, Dan, and Naphtali. 14“The Levites shall then answer and say to all the men of Israel with a loud voice, 15‘Cursed is the man who makes an idol or a molten image, an abomination to the LORD, the work of the hands of the craftsman, and sets it up in secret.’ And all the people shall answer and say, ‘Amen.’ 16‘Cursed is he who dishonors his father or mother.’ And all the people shall say, ‘Amen.’ 17‘Cursed is he who moves his neighbor’s boundary mark.’ And all the people shall say, ‘Amen.’ 18‘Cursed is he who misleads a blind person on the road.’ And all the people shall say, ‘Amen.’ 19‘Cursed is he who distorts the justice due an alien, orphan, and widow.’ And all the people shall say, ‘Amen.’ 20‘Cursed is he who lies with his father’s wife, because he has uncovered his father’s skirt.’ And all the people shall say, ‘Amen.’ 21‘Cursed is he who lies with any animal.’ And all the people shall say, ‘Amen.’ 22‘Cursed is he who lies with his sister, the daughter of his father or of his mother.’ And all the people shall say, ‘Amen.’ 23‘Cursed is he who lies with his mother-in-law.’ And all the people shall say, ‘Amen.’ 24‘Cursed is he who strikes his neighbor in secret.’ And all the people shall say, ‘Amen.’ 25‘Cursed is he who accepts a bribe to strike down an innocent person.’ And all the people shall say, ‘Amen.’ 26‘Cursed is he who does not confirm the words of this law by doing them.’ And all the people shall say, ‘Amen.’

Neh 10:30
and that we will not give our daughters to the peoples of the land or take their daughters for our sons.

They specifically made an oath not to marry their children to the pagan peoples of the nearby lands because that is a sin they had just committed previously.

Deut. 7:1-4 “When the LORD your God shall bring you into the land where you are entering to possess it, and shall clear away many nations before you, the Hittites and the Girgashites and the Amorites and the Canaanites and the Perizzites and the Hivites and the Jebusites, seven nations greater and stronger than you, 2and when the LORD your God shall deliver them before you, and you shall defeat them, then you shall utterly destroy them. You shall make no covenant with them and show no favor to them. 3“Furthermore, you shall not intermarry with them; you shall not give your daughters to their sons, nor shall you take their daughters for your sons. 4“For they will turn your sons away from following Me to serve other gods; then the anger of the LORD will be kindled against you, and He will quickly destroy you.

Neh 10:31
As for the peoples of the land who bring wares or any grain on the sabbath day to sell, we will not buy from them on the sabbath or a holy day; and we will forego the crops the seventh year and the exaction of every debt.

They will not buy or sell on the Sabbath because then they are employing servants on that sacred day of rest.

Ex. 20:8-10 “Remember the sabbath day, to keep it holy. 9“Six days you shall labor and do all your work, 10but the seventh day is a sabbath of the LORD your God; in it you shall not do any work, you or your son or your daughter, your male or your female servant or your cattle or your sojourner who stays with you.

They will not harvest crops on the seventh year.
Exod. 23:10-11
They will forgive all debts every seven years.
Deut. 15:1-5
It seems that they were to repeat specific parts of the Covenant that might be tempted by their greed.
River Valley Torah Assembly