The Creation Week
The first distinct section of the Hebrew Bible, Genesis 1:1 to 2:3, describes God's creation of Heaven and Earth, following a two-verse introduction describing a mighty wind blowing in dark emptiness over formless and timeless water*. Six days of creation are followed by a seventh day of rest corresponding to the Biblical "sabbath". Each of the six days of creation begins with God speaking.
See A prologue to Revelation by Ralph Lovelock and Alfred Norris (1940) for a reading of the creation week as a sequence of visions analogous to the visions of Revelation.
The Sabbath
The Hebrew word "sabbath," meaning both "sabbath" and "Saturday", is related to Hebrew שבע sheva' "seven" — perhaps coincidentally: see https://en.wikipedia.org/wiki/Biblical_Sabbath#Etymology.