39Then the Lord said to him, "Now then, you Pharisees clean the outside of the cup and dish, but inside you are full of greed and wickedness. 40You foolish people! Did not the one who made the outside make the inside also? 41But give what is inside the dish to the poor, and everything will be clean for you. 42"Woe to you Pharisees, because you give God a tenth of your mint, rue and all other kinds of garden herbs, but you neglect justice and the love of God. You should have practiced the latter without leaving the former undone.
Alms giving should therefore be part of our intrinsic spirituality rather than a mere response to a specific requirement. Nevertheless, there are specific Old Testament commandments that prescribe the tithing of alms once in every 3 years. In Deuteronomy 14, the Israelites were commanded to lay aside a specific tithe, once every 3 years, for the foreigners, fatherless and needy:
28 At the end of three years thou shalt bring forth all the tithe of thine increase the same year, and shalt lay it up within thy gates: 29 And the Levite, (because he hath no part nor inheritance with thee,) and the stranger, and the fatherless, and the widow, which are within thy gates, shall come, and shall eat and be satisfied; that the LORD thy God may bless thee in all the work of thine hand which thou doest.
In the overall context of tithing, the Israelites were specifically commanded to to provide 10% per year as a Levite/Temple tithe, 9% (10% of the remainder 90%) as a festival tithe and 2.7% (10% of the remaining 81%, once every 3 years) as an 'alms' tithe.
Therefore, at a personal level, apart from the 10% tithe/pledges we make annually to the church (this is not giving of alms!), we should be prepared to set aside at least 2.7% annually for 'alms' giving. Similarly, at a corporate level, since the Levites were also subject to the same principles of tithing, the annual church collection from the congregation should be prepared to set aside at least 2.7% for corporate 'alms' giving. A church with average annual receipts of ~$2 million, should therefore be prepared to allocate at least $54,000 annually towards 'alms'.
These are however, merely the legalistic old testament principles. At best, they exist as guidelines for our giving. Giving now is for us an act of grace, and a manifestation of our spirituality. We are instructed to give generously (Luke 6:38;Matt 10:8), according to what we have and not what we do not have (2Cor 8:12), cheerfully (2 Cor 9:7) and quietly (Matt 6:1-4).