The information given in Matthew 5:32 and 19:9 is extremely limited. Without a knowledge of the laws and customs of the society of that time, and the covenant of marriage solemnized by the holy priesthood in the early church, it is impossible to make a judgement on the specifics of the verses in question.
This much we can say, however. The practices of the church in the time of the Savior’s earthly ministry, and in the days of the restoration both came into being by revelation from God. If they are different from one another in any particular, they are both right and correct for the time and age in which they were revealed. It would be very hazardous to impose the same rules of conduct on two societies as disparate as the world ruled by the Romans in the time of Christ into which society the early church was required to exist and the society in which the church exists today. It appears that without more information on the subject, we must withhold judgement. Elder Bruce R. McConkie had the following to say on the subject:
“As here recorded, our Lord’s teachings about marriage and divorce are fragmentary and incomplete. They can only be understood when considered in connection with the law of celestial marriage as such has been revealed anew in modern times. These same general principles governing eternal marriage were known to and understood by the disciples in Jesus’ day and also, in part at least, by the Pharisees. But the accounts here preserved by both Matthew and Mark of the Master’s discussion on marriage and divorce are so condensed and abbreviated that they do not give a clear picture of the problem. Modern scriptural exegetes need the same background and knowledge possessed by those who engaged in the original discussion” (Bruce R. McConkie, Doctrinal New Testament Commentary, Vol. 1, p 546).