It is narrated from Sahl bin Sa’d Al-Sa’idi (may Allah be pleased with him) that a woman came to the service of the Prophet ﷺ and said: “O Messenger of Allah! I have gifted myself to you.” She stood for a long time. Then a companion stood up and said: “O Messenger of Allah! Marry her to me if you have no need of her.” The Messenger of Allah ﷺ said to him: “Do you have anything to give her as a dowry?” That companion (may Allah be pleased with him) said: “I have nothing except this lower garment.” The Prophet ﷺ said: “If you give her that, you will sit down without a lower garment. Look for something else.” He said: “I find nothing.” The Prophet ﷺ said: “Look, even if it is an iron ring.” The companion searched but found nothing. So the Messenger of Allah ﷺ said to him: “Do you know anything of the Qur’an by heart?” He said: “Yes, such and such surahs,” and he named the surahs. Upon this, the Messenger of Allah ﷺ said: “I have married her to you for the dowry of what you know of the Qur’an (i.e., you will teach her).”
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1117
Hadith Takhrijاخرجه البخاري ، الوكالة ، باب وكالة المرأة الامام في النكاح (2310)، (5029)، (5030)، ومسلم، النكاح ، باب الصداق جواز كونه تعلیم قرآن و خاتم حديد ..... الخ (1425)۔
It is narrated from Sahl (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) married a woman to a man in exchange for some chapters of the Qur'an.
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1118
It is narrated from Abu Hazim bin Dinar that he heard Sahl bin Sa’d Al-Sa’idi (may Allah be pleased with him) say that a companion sent a proposal of marriage to a woman who was standing near the Prophet (ﷺ). The Prophet (ﷺ) spoke to him about her dowry and said: “Go and look, even if it is only an iron ring.”
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1119