First, let's define "tithe." A tithe is 10 percent. In the Mosaic Law, the Jews were commanded to give 10 percent of everything they earned and grew to the Tabernacle/Temple (Leviticus 27:30; Numbers 18:26; Deuteronomy 14:24; 2 Chronicles 31:5). Actually, the law required multiple tithes, which totaled about 23.3 percent, not 10 percent. But the Bible is clear that the requirement in the Mosaic Law to tithe was for the nation of Israel, not for all godly people.
Should Christians tithe on miscellaneous income, such as inheritance, gifts, legal settlements, winnings, tax refunds, etc.?
Christ came to fulfill the law (Matthew 5:17), so we Christians are not constrained to obey the law. Jesus' requirement is much harder than tithing. Everything we have belongs to God, not just a portion. (1 Timothy 6:7; Psalms 24:1; Haggai 2:8) Our task is to be good stewards of what He has entrusted to us (Matthew 25:14-30; 1 Timothy 6:18). The New Testament requirement for giving is much more demanding than the Old Testament requirement to tithe.
The New Testament specifically addresses giving in 1 Corinthians 16:1-2, where it says "Now concerning the collection for the saints: as I directed the churches of Galatia, so you also are to do. On the first day of every week, each of you is to put something aside and store it up, as he may prosper, so that there will be no collecting when I come." The Greek word translated "as he may prosper" is actually a passive verb which also could be translated "as he may be prospered." The implication is that God is doing the prospering, and this prospering includes all that God has provided: house, belongings, wages, inheritances, gifts, winnings, tax refunds, legal settlements, and so on. The Corinthians apparently didn't fully understand the principle here, so Paul again addressed the issue of giving in 2 Corinthians 9. In specific, verses 6 and 7 say, "The point is this: whoever sows sparingly will also reap sparingly, and whoever sows bountifully will also reap bountifully. Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver." Paul was emphasizing that Christian giving is not governed by rules but by the heart. If our heart is in tune with God, we will give cheerfully and not under compulsion. It is not the amount that we give (consider Jesus' comments about the widow's two mites, Mark 12:41-44) or the percentage we give, but the attitude with which we give that matters. For God "… looks on the heart" (1 Samuel 16:7) rather than on outward appearances.
So Christians are not constrained to tithe, but to give based on all that God has provided, which includes miscellaneous income, i.e. inheritance, gifts, winnings, tax refunds, legal settlements, etc. As we should do in all areas of our lives, we should seek wisdom from God concerning the disposition of our resources, and He has promised to give it generously (James 1:5). Then we will give cheerfully.
Christian tithing - What does the Bible say?
Are tithes and offerings the same thing? Do Christians have to give tithes and offerings?
When tithing a percentage of my income, should it all go to my home church or can I give some to a Christian ministry?
When tithing a percentage of my income, should it be off the net or the gross?
What does it mean to be a cheerful giver?
Truth about the Christian Life