With 176 verses, this is the longest Psalm and chapter in the Bible. It is an acrostic poem of one who delights in the Law God gave His chosen.
When one chooses a path, the path leads to doors which may open, which would never have opened were the path not chosen. The path of the Law God gave his chosen works that way too.
Walking in the dark, one stumbles on things they cannot see. The light He provides allows one to travel in safety.