The Lord wanted His people to tithe, even when they were traveling, and the same holds true for the Christian. I know of no New Testament principle that releases Christians from giving to their home congregation, or to a congregation that they are visiting when traveling. After stating that the Israelites were to give the tithe, Moses then wrote this,

“But if the journey is too long for you, so that you are not able to carry the tithe, or if the place where the Lord your God chooses to put His name is too far from you, when the Lord your God has blessed you, then you shall exchange it for money, take the money in your hand, and go to the place which the Lord your God chooses. And you shall spend that money for whatever your heart desires: for oxen or sheep, for wine or similar drink, for whatever your heart desires; you shall eat there before the Lord your God, and you shall rejoice, you and your household. You shall not forsake the Levite who is within your gates, for he has no part nor inheritance with you” (Deuteronomy 14:24–27).

The Lord made provisions for when an Israelite was away from home, but still the Israelite had to pay the tithe. Likewise, when you are gone from your home congregation, it has still to keep its obligations. Therefore, leave your contribution behind for someone to put it into the church treasury, or make it up when you get back. Leave something for the church where you are visiting also.