Two weeks ago, the opening verses of this psalm were one of the alternative responses to the reading from Genesis 29, the story of Jacob's marriages. See Prayer Checklist.
This week, Psalm 105 is also a response to a reading from Genesis, this time the story of the effects of jealousy among Joseph's brothers.
The psalm begins with the reminder to praise the Lord, both by singing to the Lord and by telling others, continuing to ask the Lord for what we need and continuing to remember what the Lord has already done for us.
The verses added for this week's reading recount the story of Joseph in Egypt. Although he had come as a captive, he rose to the role of the king's helper. He was able to protect Egypt from famine. The brothers, because they were jealous, had wanted to get rid of him. He became a slave in a foreign country. Yet, God was able to use Joseph to help that country and, eventually, to help those same brothers that had tried to get rid of him.