What might qualify as grounds for divorce by mercy or intent?
Jesus taught principles of mercy (Matt 12:1-8) and intent (Mark 2:23-28) regarding the Sabbath, which may easily and righteously also be applied to marriage (Pr 21:3; Hos 6:6; Jn 7:24). Consider a husband that beats his wife, but does not commit adultery or desert her. A husband that threatens his wife, but does not commit adultery or desert her. A spouse that defrauds the other spouse sexually. A husband that is a habitual drunkard and/or verbally abuses wife or children. A husband that spends all income on gambling, drinking, or his hobbies, etc. These two principles are precious indeed, but they should be applied carefully in light of scripture, and each marriage situation must be judged individually. Reconciliation should be sought first.
Proverb commentary about just judgment and mercy: Proverbs 21:3.