Remember the Sabbath day, to keep it holy. Six days shalt thou labour, and do all thy work: But the Seventh day is the Sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates: For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the Seventh day: wherefore the LORD blessed the Sabbath day, and hallowed it.
Exodus 20:8-11
The numeral seven appears in the Bible to an overwhelmingly lopsided degree. From the very beginning, in Genesis Chapter 2, the seventh day is set apart. The suggestion is very strong in the Book of Genesis, and then later strengthened throughout the entire Bible, that God performed His usual practice of resting on the Seventh day, that this is what He had been doing throughout eternity, working six days and resting on the Seventh. Referring to this great occurence, this resting after the creation of the world, in the very heart of the Ten Commandments God significantly calls the Seventh day: "the Sabbath of Yahweh thy God" - the Seventh day is God's day. This ringing Truth is later strengthened in the Book of Isaiah where Yahweh Himself again declares about the Seventh day: "My Holy day."
Of God Himself, the numeral seven is amazingly important, as the Bible several times spells out "Seven Spirits of God" (Revelation 1:4, 4:5 and 5:6, which possibly might be referring to the sevenfold attributes of God as depicted in Isaiah 11:2).
Here is a random sampling of the numeral SEVEN in the Bible, and this short list is in no way comprehensive or all-inclusive, as the Bible has an exhaustive use for the number seven:
The seven good kine are seven years; and the seven good ears are seven years: the dream is one. Genesis 41:26
And he passed over before them, and bowed himself to the ground seven times, until he came near to his brother. Genesis 33:3
And he made his seven lamps, and his snuffers, and his snuffdishes, of pure gold. Exodus 37:23
And the priest shall dip his finger in some of the blood, and sprinkle it seven times before the LORD, even before the vail. Leviticus 4:17
And he sprinkled thereof upon the altar seven times, and anointed the altar and all his vessels, both the laver and his foot, to sanctify them. Leviticus 8:11
And the priest shall dip his right finger in the oil that is in his left hand, and shall sprinkle of the oil with his finger seven times before the LORD: Leviticus 14:16
And seven priests shall bear before the ark seven trumpets of rams' horns: and the seventh day ye shall compass the city seven times, and the priests shall blow with the trumpets. Joshua 6:4
He shall deliver thee in six troubles: yea, in seven there shall no evil touch thee. Job 5:19
And the seven angels came out of the temple, having the seven plagues, clothed in pure and white linen, and having their breasts girded with golden girdles. Revelation 15:6
And I saw the seven angels which stood before God; and to them were given seven trumpets. Revelation 8:2
And I turned to see the voice that spake with me. And being turned, I saw seven golden candlesticks; And in the midst of the seven candlesticks one like unto the Son of man, clothed with a garment down to the foot, and girt about the paps with a golden girdle. His head and his hairs were white like wool, as white as snow; and his eyes were as a flame of fire; And his feet like unto fine brass, as if they burned in a furnace; and his voice as the sound of many waters. And he had in his right hand seven stars: and out of his mouth went a sharp twoedged sword: and his countenance was as the sun shineth in his strength. And when I saw him, I fell at his feet as dead. And he laid his right hand upon me, saying unto me, Fear not; I am the first and the last: I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death. Revelation 1:12-18
The words of the LORD are pure words:as silver tried in a furnace of earth, purified seven times. Psalm 12:6