What does Psalm 90:7 mean?

At Kadesh Barnea the people of Israel refused God's command, and the advice of Joshua and Caleb, to enter Canaan, the land God had promised to them. As a result of their disobedience, they were sentenced to wander for forty years in the wilderness until the older generation died (Numbers 14:33–35). The sentence was imposed because God was angry with their decision. Exodus 34:6 describes God as merciful and slow to anger. However, Israel's frequent disobedience and unbelief provoked Him.

Numbers 11 reports the typical rebellious attitude the people showed toward the Lord. They "complained in the hearing of the LORD about their misfortunes" (Numbers 11:1) and wept and said, "Oh that we had meat to eat! We remember the fish we ate in Egypt that cost nothing, the cucumbers, the melons, the leeks, the onions, and the garlic. But now our strength is dried up, and there is nothing at all but this manna to look at" (Numbers 11:4–6). Rather than thanking God for freeing them from oppressive slavery in Egypt and keeping them from starvation as they journeyed toward the Promised Land, they complained that the food was not good enough.