A song of praise from David, when the Ark of the Covenant finally got to its destination. This poem actually crams part or most of three psalms together: 105, 96 and a little of 106 (in that order).
It was a city, specifically the capital of the rebel territory after Israel split in two. But in time “Samaria” was the name of that entire region – not just the city. This started when the Assyrian Empire took over the region and continued through Jesus’ day.
A group of people that remains. Generally, in the Bible, it describes the last surviving few of a group, like the only faithful people left.
Jewish exiles return to their homeland – or their ancestor’s land, since most of these exiles were born in Babylon*. Over the course of about a century, the Jews rebuild the temple and the walls of Jerusalem. Plus, some other drama.
There was only one (at a time), and it was in Jerusalem. Jews in 2021 may refer to synagogues as Temple Beth Something, but this is not biblical language. In the Bible, the temple is a single place (albeit one that was rebuilt a few times). Also, it is sometimes called “the house of the LORD.”
David is begging for mercy after he sinned egregiously with Bathsheba. (We know this is the theme because the Psalm itself tells us in the heading.)
The same young man that killed Goliath was also one of the very best kings in Israel’s history. He is the great-grandson of Ruth (yes, that Ruth – read the end of her book) and ancestor to Jesus Christ (Matt 1:1, also v. 16). He also wrote at least 75* of the 150 psalms in Psalms. He was architect of the temple.