Imrei Emet: Shabbat Prayers: “They Shall Rejoice”
“They shall rejoice in Your kingship, those who observe the Sabbath and call it a delight.” It is most appropriate for a human being to strive to derive happiness from the Sabbath, as it is written, “On the day of your happiness (Numbers 10:10),” and the Midrash teaches this refers to the Sabbath.
When we recite the words, “they shall rejoice in Your kingship,” we must remember that the most powerful way to derive happiness from the Sabbath is through our faith that such happiness exists and is accessible, as is taught in the holy Zohar (Volume 2, page 88), “The Sabbath meals are meals of faith.” In proportion to our faith that the Sabbath is able to help us achieve happiness, and to the degree we grasp onto that faith and its happiness, so will the Sabbath purify us from all thoughts that would deprive us from its eternal joy. (Imrei Emet)