Should Christians tithe on miscellaneous income, such as inheritance, gifts, legal settlements, winnings, tax refunds, etc.?

from the old testament

• In the Mosaic Law, Jews were commanded to give ten percent of everything they earned and grew to the Tabernacle/Temple (Leviticus 27:30). In fact, the law required multiple tithes, which totaled about 23.3 percent.
• The Bible is clear that the requirement in the Mosaic Law to tithe was for the nation of Israel, not for all godly people. When we give, we should remember that God "… looks on the heart" (1 Samuel 16:7) rather than on outward appearances, so we should be giving with the right intentions.
• Through the prophet Micah, God challenged the Israelites to give without neglecting the heart condition that undergirded the sacrifices: “He has told you, O man, what is good; and what does the Lord require of you but to do justice, and to love kindness, and to walk humbly with your God?” (Micah 8:6). The same principle should guide Christian giving.

from the new testament

• Christ came to fulfill the old law (Matthew 5:17), so Christians are not constrained to obey it. Jesus' requirement is much harder than tithing.
• The amount or percentage we give is unimportant, but the intentions with which we give matter (Mark 12:41-44).
• First Corinthians 16:1-2 specifically addresses giving: "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 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. 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." This is not a “give to get” scheme as some Word-of-Faith preachers say. Rather, it is recognizing that God gives us everything we have, so we should have an open heart and hand when it comes to His kingdom.

implications for today

While Christians are not constrained to tithe certain percentages of our income, we should give based on all that God has provided to us, which includes miscellaneous income, inheritance, gifts, winnings, tax refunds, legal settlements, and so on. As we should do in all areas of our lives, we must seek wisdom from God concerning the disposition of our resources, and He has promised to give His wisdom generously (James 1:5). 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. Ultimately, we can apply to our life Paul’s instruction to Christians in 1 Timothy 6:18-19: “They are to do good, to be rich in good works, to be generous and ready to share, thus storing up treasure for themselves as a good foundation for the future, so that they may take hold of that which is truly life.” To put it simply, our “wealth” should be displayed in our godliness, not in our material possessions.