This is the start of the “Song for the Sabbath day.” What’s the connection between Shabbos and praising G-d? The Radak explains that Shabbos is the best time to thank G-d because we are freed of our usual worldly distractions. On Shabbos, our souls are unencumbered by the mundane things that typically weigh us down, enabling us to praise G-d with much greater focus.