In Psalm 104, we are encouraged to think about how God made all things, and provides for his creation. The psalmist’s response is praise. We can think about how much we think about God in our everyday lives, and how wide is his creative work.
Psalm 105 gives praise to God, and his people need to turn to him. Israelites were saved not because they were mighty – there weren’t many of them when they went toward the promised land – but because of God’s help. The psalmist recalls all the plagues of Egypt, which God ended up using for God in caring for his people.