WAS TITHING A COMMAND, LAW, OR ORDINANCE?
The first tithe, aka priesthood tithe, was called a command, a law, and an ordinance in the scriptures.
God defined His tithe in Leviticus 27:30-33.
Leviticus 27:34 (KJV) These are the commandments, which the LORD commanded Moses for the children of Israel in mount Sinai.
Malachi 3:7-8 (KJV)
7 Even from the days of your fathers ye are gone away from mine ordinances, and have not kept them. Return unto me, and I will return unto you, saith the LORD of hosts. But ye said, Wherein shall we return?
8 Will a man rob God? Yet ye have robbed me. But ye say, Wherein have we robbed thee? In tithes and offerings.
Hebrews 7:5 (KJV) And verily they that are of the sons of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people according to the law, that is, of their brethren, though they come out of the loins of Abraham: