What is the biblical basis for Christians being instructed to tithe (10%) of their income to the modern day 'church'?

I understand the commandment (principle & purpose) of tithing to the Levitical priesthood as defined in OT passages such as Leviticus 27, Numbers 18, etc. But, my question is now (present day), when there is no temple or clear lineage of the sons of Aaron, what biblical proof texts do Christian (mostly Gentile) pastors use to claim that modern-day believers are *commanded* to tithe to them (namely, their non-profit organization) as obedience to God?