What is the ruling regarding a husband telling his wife: "Talking between us is forbidden," or "Each one of us is in a room," with the intention of threatening a quarrel, and what is the ruling regarding doubting the wording of the statement due to obsessive whispering (waswasah)?

If the husband says to his wife: "If you do such and such, then speech between me and you is forbidden," this is a prohibition of what is permissible. The preponderant opinion is that it becomes an oath (yamin), and an expiation for breaking an oath (kaffarat yamin) becomes obligatory if the husband breaks his oath due to the wife doing the action upon which the prohibition was conditioned. This statement does not result in divorce (talaq) or ẓihār, unless the husband intended ẓihār by it. However, if he did not condition the prohibition of speech upon an action, then an expiation for breaking an oath becomes immediately obligatory.