Reference: Sahih al-Bukhari,Book of wedlock,marriage(nikaah),
Chapter of if the suitor says, "Marry me to so-and-so," and the guardian says, "I have married her to you for such Mahr"
AUTHENTIC HADITH:
Narrated Sahl:
A woman came to the Prophet(SAWS),, and presented herself to him (for marriage). He said, "I am not in need of women these days." Then a man said, "O Allah's Messenger (SAWSﷺ)! Marry her to me." The Prophet (SAWSﷺ) asked him, "What have you got?" He said, "I have got nothing." The Prophet (SAWSﷺ) said, "Give her something, even an iron ring." He said, "I have got nothing." The Prophet (SAWSﷺ) asked (him), "How much of the Qur'an do you know (by heart)?" He said, "So much and so much." The Prophet (SAWSﷺ) said, "I have married her to you for what you know of the Qur'an."
