The Torah says God blessed the seventh day and sanctified it. Targum Pseudo-Jonathan on (Genesis 2:3) lets the sentence expand: the Lord blessed the seventh day more than all the days of the week, and sanctified it, "because in it He rested from all His works which the Lord had created and had willed to make."
The small addition — "more than all the days" — changes the math. Shabbat is not just one of seven. It is elevated above the other six. Each day of creation received the blessing of existence; only Shabbat received the additional blessing of kedusha, holiness. Every Jew who welcomes Shabbat each week is receiving a day that was singled out and crowned before any human being existed to notice.