Hey FEN,the Malachi verse is the ones that pertain to giving,although I don't see tithes in the NEW TESTAMENT.PAUL speaks continually about an offering,giving liberally out of your poverty(church @ THESSOLNICA)
We can all look and see what Mal. 3:10 says, but do take the time to look in the earlier chapters to study(not just read) what was happening, so that we can develop context.
In essence, the nation was "playing church"...they had gotten sloppy in both their personal lives, and in corporate worship. There was open idolatry, false teaching,false prophecy, and improper ministry. The prophet was being used to bring correction and restore order, for them to return to the instructions giving them in regards to personal living, and public worship, specifically their giving. (notice they were sacrifing sick, and lame lambs, instead of strong unblemished ones, and the priest were not even burning incense at times)
In 3:10, they are given instruction to return order, and it starts with us
1.They were to bring the tithe into the storehouse(which was a layed aside place in the tabernacle and later the temple), and the purpose of meat being at the storehouse(a distribution center), was for care for the priest,levite, temple needs, orphans,widows, and the poor (all throughout Numbers & Leviticus)
**We incorrectly depend on the govenments social welfare programs to do, what Gods order intended the church to do
2. After they took care of the bringing the tithe, it was God's responsibility to take care of the other...pour out a blessing, open windows of heaven, rebuke the devour etc
so obedience and humility, creates opportunity for greater measure of blessing
Tithing is briefly mentioned by Jesus in Luke 11, and Matt 23. Jesus DOES NOT condemn tithing, in fact he encourages the pharisees to tithe, he just also tells them to also, or in addition ,pay attention to the weightier matters of the word, faith, hope, justice, etc
I have not been able to see where Jesus teaches more specifically on actual amounts or percentages(he did believe in paying taxes though..lol)...but you do see Paul teachings on giving in regards to the same issues that the Old Testament describe tithes usage for:
1. those who minister being supported (I Cor. 9)
2. taking care of the poor and needy (Gal. 2, I Cor. 16)
3. For the work of the ministry
So scripture does not contradict itself in regards to tithing and giving. God does not need or want our money, he wants our heart, but if he truly has our heart, tithing and giving would not be an issue
When giving, YES do so with a willing and cheerful heart, do so knowing that your obedience will open you to a level of blessing and favour(and expect to receive as such), and give knowing that whatever measuring cup you use to give, will be the one that is used to give back to you.(Luke 6:38)
Finally, we give as unto God, I know there are real people who handle(mishandle), and administer(misadminister) the meat, and storehouse, but I don't give unto them, God will deal with them. I also understand that our culture is filled with Crooks & Clowns(the false teachers who twist, and rape the people of God for material gain)...but please don't let this deter you from properly giving, be encouraged to know that the Lord is the righteouss paymaster (where is that spell check icon)...follow God's order, and you will have God's results