The tithe was part of that old law. The Jews were still under it when Jesus walked the earth. The purpose of Jesus coming was to free Israel from that law and to tear down that wall of law so Gentiles could also experience freedom and life. We abide in a different covenant and are not under any of the old law. And yet, church incorporated can’t resist cherry picking a few of their chosen favorites from that obsolete package. The tithe is usually one of them. Even Jesus stated the tithe was about food—not money and not all of your income.
Under the law, tithing was a requirement for the sake of the priestly Levitical tribe, as they received a tenth of the food from the other tribes of Israel. Now in Christ, we freely give as motivated by perfect love.