Gen.7[2] Of every clean beast thou shalt take to thee by sevens, the male and his female: and of beasts that are not clean by two, the male and his female.

[8] Of clean beasts, and of beasts that are not clean, and of fowls, and of every thing that creepeth upon the earth,[9] There went in two and two unto Noah into the ark, the male and the female, as God had commanded Noah.

Matt.13:[24] Another parable put he forth unto them, saying, The kingdom of heaven is likened unto a man which sowed good seed in his field:
[25] But while men slept, his enemy came and sowed tares among the wheat, and went his way.
[26] But when the blade was sprung up, and brought forth fruit, then appeared the tares also.
[27] So the servants of the householder came and said unto him, Sir, didst not thou sow good seed in thy field? from whence then hath it tares?
[28] He said unto them, An enemy hath done this. The servants said unto him, Wilt thou then that we go and gather them up?

[36] Then Jesus sent the multitude away, and went into the house: and his disciples came unto him, saying, Declare unto us the parable of the tares of the field.
[37] He answered and said unto them, He that soweth the good seed is the Son of man;
[38] The field is the world; the good seed are the children of the kingdom; but the tares are the children of the wicked one;
[39] The enemy that sowed them is the devil; the harvest is the end of the world; and the reapers are the angels.

[43] Then shall the righteous shine forth as the sun in the kingdom of their Father. Who hath ears to hear, let him hear.

[45] Again, the kingdom of heaven is like unto a merchant man, seeking goodly pearls:
[46] Who, when he had found one pearl of great price, went and sold all that he had, and bought it.

[47] Again, the kingdom of heaven is like unto a net, that was cast into the sea, and gathered of every kind:
[48] Which, when it was full, they drew to shore, and sat down, and gathered the good into vessels, but cast the bad away.

[51] Jesus saith unto them, Have ye understood all these things? They say unto him, Yea, Lord.

[52] Then said he unto them, Therefore every scribe which is instructed unto the kingdom of heaven is like unto a man that is an householder, which bringeth forth out of his treasure things new and old.

Lev.7[21] Moreover the soul that shall touch any unclean thing, as the uncleanness of man, or any unclean beast, or any abominable unclean thing, and eat of the flesh of the sacrifice of peace offerings, which pertain unto the LORD, even that soul shall be cut off from his people.

Lev.11[46] This is the law of the beasts, and of the fowl, and of every living creature that moveth in the waters, and of every creature that creepeth upon the earth:[47] To make a difference between the unclean and the clean, and between the beast that may be eaten and the beast that may not be eaten

Lev.14[54] This is the law for all manner of plague of leprosy, and scall,[55] And for the leprosy of a garment, and of a house,[56] And for a rising, and for a scab, and for a bright spot:[57] To teach when it is unclean, and when it is clean: this is the law of leprosy.

1Cor.10[21] Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lord's table, and of the table of devils.

2Cor.6[14] Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?[15] And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?
[16] And what agreement hath the temple of God with idols?

for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people.

Heb.7[26] For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens;

Eph.5 [11] And have no fellowship with the unfruitful works of darkness, but rather reprove them.[12] For it is a shame even to speak of those things which are done of them in secret.

Prov. 1[10] My son, if sinners entice thee, consent thou not.[11] If they say, Come with us, let us lay wait for blood, let us lurk privily for the innocent without cause:[12] Let us swallow them up alive as the grave; and whole, as those that go down into the pit:[13] We shall find all precious substance, we shall fill our houses with spoil:[14] Cast in thy lot among us; let us all have one purse:[15] My son, walk not thou in the way with them; refrain thy foot from their path:
[16] For their feet run to evil, and make haste to shed blood.[17] Surely in vain the net is spread in the sight of any bird.[18] And they lay wait for their own blood; they lurk privily for their own lives.[19] So are the ways of every one that is greedy of gain; which taketh away the life of the owners thereof

Ezra 6:21 And the children of Israel, which were come again out of captivity, and all such as had separated themselves unto them from the filthiness of the heathen of the land, to seek the LORD God of Israel, did eat, 22 And kept the feast of unleavened bread seven days with joy: for the LORD had made them joyful, and turned the heart of the king of Assyria unto them, to strengthen their hands in the work of the house of God, the God of Israel.

Ezra 10:10 And Ezra the priest stood up, and said unto them, Ye have transgressed, and have taken strange wives, to increase the trespass of Israel.
11 Now therefore make confession unto the LORD God of your fathers, and do his pleasure: and separate yourselves from the people of the land, and from the strange wives.

Havdalah is Hebrew for separation. It refers to separating the sacred from the ordinary, the sacred being the Sabbath day and the ordinary being the other days of the week.