unlike a sale: a sale is not valid except at the customary price, whereas marriage is broader in this respect.
If they deceived this husband and said to him, “Perhaps you could give us one hundred riyals as a bridal gift,” and he replied, “No—not even ten riyals,” and they said, “That is no problem,” whereupon he married her, then we say: You must pay the customary bridal gift—fifty thousand. At first, he had refused one hundred riyals, yet this poor husband is now obliged to pay fifty thousand. According to Shaykh al-Islam’s view, however, the marriage contract is invalid and the woman is not lawful for him. This is easier for him, provided that he has not consummated the marriage. But if he has consummated it, he must pay the customary bridal gift, and the two are to be separated.
For this reason, in such matters one should be knowledgeable in jurisprudence. For example, if a husband divorces his wife for the first time, he has the right to take her back. But if his wife gives him even one riyal, he no longer has the right to take her back.
His statement, “or no maintenance”: that is, the husband stipulates that he will not provide for her. It is well known that a husband is required to provide maintenance for his wife once he has contracted marriage with her and she has come into his possession. If he stipulates this and she accepts, the marriage is valid, because this does not relate to the essence of the contract. However, the condition itself is invalid because it conflicts with what the contract entails. The Prophet, peace and blessings be upon him, said: “Their provision and clothing are your responsibility, according to what is customary.” (1) He said this in the Farewell Pilgrimage sermon. Thus, if he negates maintenance, he has contradicted the hadith. The Prophet, peace and blessings be upon him, also said: “Every condition not found in the Book of Allah is invalid, even if there are a hundred conditions.” (2)