10  Now I command married people,  although it is  [really]  the Lord’s command  [See.  Mark 10:2-12]:  A wife should not separate from her husband.  [Note:  This act implies the intention of pursuing a legal and permanent breach of the marriage relationship by divorce.  “Separate” and “divorce” appear to be used interchangeably in this section.  See verses 11-15]. 
1 Corinthians 7:10 Cross References - AUV
Matthew 5:32
32  But I say to you,  every person who divorces his wife makes her become sexually unfaithful to him  [i.e.,  since she will probably marry someone else],  unless the reason for the divorce is that she had  [already]  become sexually unfaithful to him.  And whoever marries a woman who has been divorced commits sexual sin with her  [i.e.,  because she is still rightfully married to her first husband]. 
Matthew 19:3-9
3  Some Pharisees came to Him,  [attempting]  to put Him to a test.  They said,  “Is it permissible by the law of Moses for a man to divorce his wife for any reason  [he chooses]?” 
4  And He answered them,  “Have you not read  [Gen.  1:27;  5:2]  that when God created  [mankind as]  male and female, 
5  He said  [Gen.  2:24],  ‘For this reason  [i.e.,  since He made one woman for one man],  a man will leave  [the home of]  his father and mother and will cling to his wife,  [so that]  the two of them will  [then]  become one flesh  [i.e.,  united in such a close relationship as to constitute one body]?’ 
6  So,  [upon becoming husband and wife]  they no longer function  [entirely]  as two persons,  but  [as]  one body.  Therefore,  those whom God  [so]  joins together  [in the marriage bond],  no person must  [ever]  separate.” 
7  They replied,  “Why then did Moses order  [a man]  to provide a legal divorce decree  [Deut.  24:1],  and then divorce his wife?” 
8  Jesus said to them,  “Moses permitted you to divorce your wives  [only]  because of the rebellious spirits you  [Jews]  had.  But this was not how it was  [intended to be]  from the beginning  [i.e.,  when God created one woman for one man]. 
9  And I tell you,  whoever divorces his wife and marries another woman commits sexual unfaithfulness  [toward her],  unless the reason for the divorce was sexual unfaithfulness  [on his wife’s part].  And the person who marries a woman who has been divorced commits sexual sin with her  [i.e.,  because she is still rightfully married to her first husband].” 
Mark 10:11-12
Luke 16:18
18  “Every person who divorces his wife and marries another woman becomes sexually unfaithful to her  [i.e.,  because he is still regarded by God as married to his first wife.  See Matt.  19:9].  And the person who marries someone who has been divorced by her husband commits sexual sin with her  [i.e.,  because she is still rightfully married to her first husband]. 
1 Corinthians 7:6
6  But I am telling you this by way of  [granting you]  permission and not as a command. 
1 Corinthians 7:12
12  But I,  not the Lord,  say this to the rest of you  [Note:  Paul now addresses the matter of mixed marriages,  a circumstance Jesus never taught about]:  If any brother has a wife who is an unbeliever,  and she agrees to continue living with him  [Note:  In these verses Paul addresses a situation where one marriage partner is converted after they are married],  he should not divorce her. 
1 Corinthians 7:15
15  Yet if the unbelieving mate separates  [from his spouse],  let him go.  The brother or sister is not obligated  [to continue the marriage]  under such circumstances.  For God has called you  [believers]  to live in peace. 
1 Corinthians 7:25
25  Now I have no command from the Lord concerning  [what you wrote about]  unmarried women.  [Note:  The word here is “virgins” but some think it includes both males and females].  But I give my advice as someone who has received the Lord’s mercy to be counted trustworthy. 
1 Corinthians 7:40
40  But she will be happier if she remains as she is  [i.e.,  single].  This is my advice and I think that I,  too,  have God’s Holy Spirit.