Also after paying the 3rd tithe the tithers were required to offer a specific declaration and a prayer as prescribed in Deuteronomy 26:13-15. There are no instructions in the Mosaic law to offer any specific prayer after paying the 1st or 2nd tithes.
Yes, there are 3 important proofs outside the 66 books of the Bible.
Antiquities of the Jews – Book 4, Chapter 8 and verse 22
“Besides those two tithes, which I have already said you are to pay every year, the one for the Levites, the other for the festivals, you are to bring every third year a third tithe to be distributed to those that want; to women also that are widows, and to children that are orphans.”
Tobit the son of Tobiel, son of Ananiel, son of Aduel, son of Gabael, of the descendants of Asiel and the tribe of Naphtali in his own words.
Tobit 1:6 – But I alone went often to Jerusalem for the feasts, as it is ordained for all Israel by an everlasting decree. Taking the first fruits and the tithes of my produce and the first shearings, I would give these to the priests, the sons of Aaron, at the altar.
Tobit 1:7 – Of all my produce I would give a tenth to the sons of Levi who ministered at Jerusalem; a second tenth I would sell, and I would go and spend the proceeds each year at Jerusalem;
Tobit 1:8 – the third tenth I would give to those to whom it was my duty, as Deborah my father’s mother had commanded me, for I was left an orphan by my father.
Christian Objections To Multiple Tithes:
How did 2.2% of Levites receive tithes from all six years from the rest of the Israelites continuously is a good question.
Here are some thoughts:
a) During their journey to the promised land, the tithing system was not implemented yet.
b) Under the leadership of Joshua - On going wars and they were still settling down.
c) During the period of Judges - Apostasy, idol worship, wars, ad hoc rulers, invasion by surrounding nations.
d) Saul-David-Solomon period: United Kingdom of Israel, establishment of Jerusalem, Kings intervention in the affairs of people which was not God's perfect will.
e) After Solomon: Divided Kingdom, Jeroboam fired Levites from their positions and appointed mean and evil people as priests, YHWH worship was abolished by Kings like Omri and Ahab, True God worship was rare. A large number of Levites/Priests and Jews loyal to YHWH migrated to the southern Kingdom during King Asa's period. Destruction of the Northern Kingdom
f) Only Southern Kingdom - Godly Kings like Hezekiah and Josiah were able to bring revival to Judah & Benjamin but those effects were destroyed by ungodly Southern Kings like Ahaz, Manasseh and other pre-exile Kings.
g) Babylonian captivity - no tithing at all.
h) Return from exile, never became a sovereign nation until 1947.
In all the above periods mentioned only during the period of Saul, David and Solomon Israelites (all 12 tribes) had the opportunity to practice YHWH's law under a stable political and religious climate. However that was not God's perfect will either in the 1st place because God wanted to be the ONLY King over all the 12 tribes. Also the taxes enforced by Kings added spin to the tithing system. Therefore the ancient Jews never had a perfect opportunity to practice the tithing laws continuously when all 12 tribes were intact. Probably during the time of certain Judges they attempted to do that but we have to bear in mind, Jerusalem was not established as God's chosen place then!