Verse 9 mentions the fatherless (orphan) and the widow. The idea is that God cares for those who can't easily provide for themselves. So how does God watch them more than He watches everyone else? The point is, God chooses to work through people to care for those who are less fortunate than others. The last part of this verse says, but the way of the wicked he turneth upside down. He is saying that God frustrates the way of the wicked. The idea is that in the end, those who don't trust in God will eventually lose as they die or their plans fail.
These last three verses (verses 7-9) challenge us that if we can't think of anything to be grateful for in our own life, at least we can always look at the world around us and see how God is working.
[10] The LORD shall reign for ever, even thy God, O Zion, unto all generations. Praise ye the LORD.
The Lord, as Israel's King, will reign forever. He gives help that no earthly king can render. This should prompt our praise to Him for how His love for people goes on forever. By studying our Bible, we can see God has been involved in the lives of people for thousands of years. God loves mankind all throughout history, even in the worst of times. Therefore, we can have faith in this same God who changes not. His loves extends for all generations.