'Three' in the Bible

Then Moses selected three cities in the Transjordan, toward the east.

At the end of every three years you must bring all the tithe of your produce, in that very year, and you must store it up in your villages.

Three times a year all your males must appear before the Lord your God in the place he chooses for the Festival of Unleavened Bread, the Festival of Weeks, and the Festival of Temporary Shelters; and they must not appear before him empty-handed.

At the testimony of two or three witnesses they must be executed. They cannot be put to death on the testimony of only one witness.

you must set apart for yourselves three cities in the middle of your land that the Lord your God is giving you as a possession.

Therefore, I am commanding you to set apart for yourselves three cities.

and then you are careful to observe all these commandments I am giving you today (namely, to love the Lord your God and to always walk in his ways), then you must add three more cities to these three.

A single witness may not testify against another person for any trespass or sin that he commits. A matter may be legally established only on the testimony of two or three witnesses.