'Three' in the Bible

Then Moses set apart three cities across the Jordan to the east,

“Three times in a year all your males shall appear before the Lord your God in the place which He chooses, at the Feast of Unleavened Bread and at the Feast of Weeks and at the Feast of Booths, and they shall not appear before the Lord empty-handed.

On the evidence of two witnesses or three witnesses, he who is to die shall be put to death; he shall not be put to death on the evidence of one witness.

you shall set aside three cities for yourself in the midst of your land, which the Lord your God gives you to possess.

You shall prepare the roads for yourself, and divide into three parts the territory of your land which the Lord your God will give you as a possession, so that any manslayer may flee there.

Therefore, I command you, saying, ‘You shall set aside three cities for yourself.’

if you carefully observe all this commandment which I command you today, to love the Lord your God, and to walk in His ways always—then you shall add three more cities for yourself, besides these three.

“A single witness shall not rise up against a man on account of any iniquity or any sin which he has committed; on the evidence of two or three witnesses a matter shall be confirmed.