This is an important point. Jews today do not "tithe."
That's because they actually know what the Law says (and the Law is extremely detailed about tithing), and they know that under today's circumstances, they can't obey the Law on tithing.
So Jews have not just made up something and called it "tithing." They admit, "We ain't tithing" and pray for forgiveness for not doing what was commanded.
What Christian churches call "tithing" is totally pulled out of thin air. No such practice is given in scripture. God described the practice of "tithing" in very precise terms, and He never described anything different and called it "tithing."
God never changed His OT definition of the tithe. Nowhere does Jesus ever say, "Moses commanded you to tithe in that way, but I tell you to tithe in this way...."
It should be remembered that during the writing of the New Testament, Jews were still doing OT tithing in Jerusalem and the Church was using the OT as scripture. If Peter or Paul or John had ever said, "We must tithe," that would have been the OT practice that was still going on. So they never said "tithe," nor did they ever describe a practice for the Church anything like it.
What they did practice (with plenty of NT witness) was giving until everyone's needs were met.