While tithing was a major part of the law God commanded Israel, tithing itself existed long before Moses was even born.
But what is tithing?
Tithing is giving 10% of something you own to someone else and keeping the rest (that is 90% of what you owned). In Hebrew, the word tithing means “a tenth” referring to the giving of 10% of to someone else [1] : specifically, the tithe as talked about in God law was giving God 10% of what you own (or something else that was valuable to you) by dedicating it to be used for his purposes (like sacrifices or building an alter) or giving it to one of his priests so it could go to help his priests who serve him.
While Nothing in the Bible is recorded of Adam or Eve nor any of their descendants before Abraham as ever giving a tithe to God: it wasn’t until the time of the patriarchs of Israel (specially Abraham and Israel [Jacob]) that the Bible first directly records tithes being given to God:
Patriarchs of Israel (Abraham and Israel) tithed to God
In two brief statements, it is recorded that both Abraham and Israel (Jacob) tithed to God (either directly as in a sacrifice or some other way, or indirectly by giving it to a priest of God to use):
Abraham gave a tithe of everything he owned (that is 10% of everything he owned) to the priest of Salem
After winning a war against Mesopotamian kings and getting back his nephew Lot, Abram (he was named Abraham later) was greeted by Melchizedek: a mysterious king of the Canaanite city-state Salem and also priest of God who praised God for his victory against these kings:
Genesis 14:18-20
"Then Melchizedek king of Salem brought out bread and wine. He was priest of God Most High, and he blessed Abram, saying, ‘Blessed be Abram by God Most High, Creator of heaven and earth. And praise be to God Most High, who delivered your enemies into your hand.’…”
After he said this, Abram did something unexpected: he gave the first tithe recorded in the Bible to this man: specifically, he gave 10% of everything he had:
Genesis 14:20
“…Then Abram gave him a tenth of everything.”
Why this was not a direct tithe to God himself, since Melchizedek was a priest of God Abram was technically giving God a tithe since he was supporting his holy priest.
Israel promises to tithe to God
Jacob (who was later named Israel) when running away from home because his brother was trying to kill him after a divine dream from God vowed to tithe to God if he helped him and blessed him as the covenant inheritor:
Genesis 28:22
“‘…And of all that you give me I will give a full tenth to you.’”
This is the first direct tithe to God recorded in the Bible where Jacob vowed to give God the 10% directly (most likely in the form of sacrifices and other things devoted to him/serving him).
Wherever the practice of tithing began with Abraham or was a custom of the ancient world he lived in; one thing is for certain: Tithing to God existed before the existence of the Old Covenant.
Source:
[1] Strong’s Hebrew #4643.--”מַעֲשֵׂר” (mah-as-ayr')--tenth part, tithe; by Biblehub
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