In Exodus 3:4, this signifies influx from the Divine. (Arcana Coelestia 6840)

10039. 'It is a sin [offering]' means that which has been purified in this manner from evils and falsities. This is clear from the meaning of 'sin', when this word is used to mean a sacrifice, as purification from evils and falsities. For in the original language, when sacrifices are the subject, sin is used to mean a sacrifice for sin; and by sacrifice purification from evils and falsities is meant, 9990, 9991. The fact that in the Word a sacrifice for sin is called a sin [offering], see Leviticus 4:3, 8, 14, 20-21, 24-25, 29, 33-34; 5:6, 8-9; 6:17, 25-26, 30, and elsewhere.