Joshua 5:11 & 12
"The day after the Passover, that very day, they ate some of the produce of the land: unleavened bread and roasted grain. The manna stopped the day after they ate this food from the land; there was no longer any manna for the Israelites, but that year they ate the produce of Canaan." NIV translation
For forty years the Israelites had eaten quail and manna but that ended with the Passover lamb. That was "deliverance food" and was basic food to get them to their destination. With the renewal of the covenant, they were back in the will of God. This deliverance food is sorta like the basics of the gospel of Jesus Christ because we just need a basic knowledge of sin and our need for a Savior to get to the point of salvation.
The Passover celebrated their deliverance and the very next day they ate food that had grown in the Promised Land. In the days to come they would have a variety of foods to eat and it reminds us of the fact that all of the scriptures are food for our souls. After we accept Jesus Christ as our Lord and Savior, we can feast on His Word and learn to appreciate Him more and more.
On the second day, the manna and quail stopped and it reminds us of the fact that there is a set amount of time for each of us to hear and either accept or reject the gospel. With this in mind, we should have a renewed sense of urgency in telling people about Jesus. As we see in Revelation, soon the "deliverance food" will cease and judgment will begin.