understand it in both senses: that which the Sacred Law recognizes and approves, and that which people customarily practice and recognize. If people have become accustomed to something forbidden, it is not permissible to act upon it, even if it is customary, because the Sacred Law does not approve of it. But whatever the Sacred Law has left unaddressed, while custom makes it binding, is binding, because this is part of what the contract entails. Contracts concluded between people include everything required by that contract, whether by the Sacred Law or by custom. Thus, if the wife says, “You did not stipulate that I should do such-and-such,” we say: “But the contract, according to customary practice, entails that you do this.”
Likewise, if the husband says, “So-and-so, prepare food, for I have men with me,” and she replies, “I will not prepare it. I married only for marital enjoyment; as for serving you, no,” is she obliged to do so or not? Yes, she is obliged, because this is what custom entails. Whatever is established by consistent custom is like that which has been expressly stipulated. Some express this by saying: “A customary stipulation is like an explicit stipulation.”
His statement, “is binding,” means binding as a matter of Sacred Law. In living with his wife in kindness, a person should not intend merely worldly happiness, companionship, and enjoyment. Rather, along with that, he should intend to draw nearer to Allah—Exalted is He—by doing what is obligatory. This is something we often neglect. Many people, in treating their wives kindly, intend that their married life should continue in the most complete manner, yet it escapes their mind that they should do so as a means of drawing nearer to Allah—Exalted is He. This is something they frequently forget, as the devils cause them to forget it. Therefore, one should intend by this that he is carrying out Allah’s command: “Live with them in kindness.” [al-Nisa 4:19] If you make this intention, you will also attain the second outcome: the continuation of a good marital life and good treatment. The same applies to the wife.