a spontaneous gift (Ex 35:29), a voluntary sacrifice (Le 22:23; Ezr 3:5), as opposed to one in consequence of a vow, or in expiation of some offence.
All the men and women, the people of Israel, whose heart moved them to bring anything for the work that the LORD had commanded by Moses to be done brought it as a freewill offering to the LORD.
You may present a bull or a lamb that has a part too long or too short for a freewill offering, but for a vow offering it cannot be accepted.
and after that the regular burnt offerings, the offerings at the new moon and at all the appointed feasts of the LORD, and the offerings of everyone who made a freewill offering to the LORD.
The Holy Bible, English Standard Version® copyright © 2001 by Crossway Bibles, a publishing ministry of Good News Publishers.