Is a woman's advising her sister with words that bring joy to her husband, such as "O apple of my eye," considered disclosing household secrets and committing a sin, taking into account the saying of the Messenger of Allah, peace and blessings be upon him: "The women among you who are from the people of Paradise are the affectionate..."?

It is permissible for a sister to utter such words to her sister with the intention of guiding her to win her husband's affection. This is for two reasons: First, these words do not reveal any of the husband's secrets. Second, it is permissible in teaching to mention what is originally forbidden, such as states of intimacy. An example of this is what Aisha, may Allah be pleased with her, narrated about her bathing with the Prophet, peace and blessings be upon him, and his touching her while she was menstruating. It would be better if the questioner mentioned these words without explicitly stating that she is addressing her husband with them.