Psalm 78 recounts the history of Israel's rebellion against God in the wilderness. Verse 30, "They didn’t turn from their cravings. Their food was yet in their mouths," specifically refers to a time when God had miraculously provided quail for the Israelites who were complaining about their diet of manna.

Here's a breakdown of the verse and its meaning:

"They didn’t turn from their cravings": This is the key part of the verse. Even while being miraculously provided for, the Israelites were still not satisfied. They were driven by their lust or desires. They lusted for meat, implying a discontentment with God's provision and a lack of trust in his wisdom and care. They prioritized their own wants over God's will.

"Their food was yet in their mouths": This emphasizes the immediacy and blatancy of their sin. God had just granted their request, yet they were already harboring new cravings and discontent. It highlights their insatiable nature and their unwillingness to learn from God's generosity. They were still enjoying the consequences of their prior complaints, and already preparing for more.

In essence, the verse conveys the following:

Ungratefulness: Despite experiencing God's provision, they remained ungrateful and focused on what they lacked.
Insatiability: Their desires were never truly satisfied, leading to a cycle of complaint and demand.
Lack of trust: Their cravings revealed a lack of faith in God's ability to provide for them and a rejection of His guidance.
Spiritual immaturity: Their behavior reflects a childish and selfish focus on immediate gratification rather than a mature understanding of God's plan.
Immediate rejection: They demonstrated their cravings right away after receiving from God.

This verse serves as a warning against the dangers of unchecked desires and a lack of contentment. It reminds us to be grateful for what we have, to trust in God's provision, and to prioritize spiritual growth over fleeting material satisfaction.