Sforno on Genesis 2:3/ספורנו על בראשית ב׳:ג׳

1ויברך אלוקים את יום השביעי, this refers not only to the first Sabbath but to all subsequent Sabbath days. G’d endowed every Sabbath with this blessing so that it would more readily accommodate the additional “soul” He grants Jews on that day. Job 33,30 describes this phenomenon as לאור באור החיים, “designed that he may bask in the light of life.” Our sages (Beytzah 16) state that the words שבת וינפש in Exodus 31,17 refer to the loss of this additional soul at the end of the Sabbath.