'Freely' in the Bible

But if his offering is made because of an oath or given freely, it may be taken as food on the day when it is offered; and the rest may be used up on the day after:

Say to Aaron and to his sons and to all the children of Israel, If any man of the children of Israel, or of another nation living in Israel, makes an offering, given because of an oath or freely given to the Lord for a burned offering;