Albert Barnes Commentary Matthew 19:10

"The disciples say unto him, If the case of the man is so with his wife, it is not expedient to marry." — Matthew 19:10 (ASV)

His disciples say, etc. The disciples were full of Jewish notions. They thought that the privilege of divorcing a wife when there was a quarrelsome disposition, or anything else that rendered the marriage unhappy, was a great privilege, and that in such cases, to be always bound to live with a wife was a great calamity. They said, therefore, that if that was the case—if such was the condition on which men married—it was better not to marry.