In Exodus 16:11-13, the Lord had graciously supplied quail when the people complained, and He did not rebuke them for questioning Him. Now, however, there was no excuse for their lack of faith. He had also given them the law since that first experience, and they had covenanted to obey it. Thus discipline was doubly justified at this point.

Source:

KJV Defenders Study Bible, by Dr. Henry Morris, Ph.D.
Publisher: Thomas Nelson
Language: English
DEF 10 ISBN 0-529-10444-x
DEF 10-1 ISBN 0-529-10445-8