I think that verse is clearly talking about when one is divorced without just cause.
Fornication is just cause. So if the man divorced his wife for anything besides fornication then they were not legally divorced they were both still married.
Hi Deborah13
Luke 16:18 "Everyone who divorces his wife and marries another commits adultery, and he who marries one who is divorced from a husband commits adultery.
Mark 10:2 Some Pharisees came up to Jesus, testing Him, and began to question Him whether it was lawful for a man to divorce a wife.
Mark 10:3 And He answered and said to them, "What did Moses command you?"
Mark 10:4 They said, "Moses permitted a man TO WRITE A CERTIFICATE OF DIVORCE AND SEND her AWAY."
Mark 10:5 But Jesus said to them, "Because of your hardness of heart he wrote you this commandment.
Mark 10:6 "But from the beginning of creation, God MADE THEM MALE AND FEMALE.
Mark 10:7 "FOR THIS REASON A MAN SHALL LEAVE HIS FATHER AND MOTHER,
Mark 10:8 AND THE TWO SHALL BECOME ONE FLESH; so they are no longer two, but one flesh.
Mark 10:9 "What therefore God has joined together, let no man separate."
Mark 10:10 In the house the disciples began questioning Him about this again.
Mark 10:11 And He *said to them, "Whoever divorces his wife and marries another woman commits adultery against her;
Mark 10:12 and if she herself divorces her husband and marries another man, she is committing adultery."
Neither Luke nor Mark have mention of any 'just cause' for divorce
Does Jesus say that 'just cause' given by Moses was "because of your hardness of heart"
Paul says that only death can separate the two, without one becoming an adulterer.
Rom 7:2 For the married woman is bound by law to her husband while he is living; but if her husband dies, she is released from the law concerning the husband.
Rom 7:3 So then, if while her husband is living she is joined to another man, she shall be called an adulteress; but if her husband dies, she is free from the law, so that she is not an adulteress though she is joined to another man