Yahya bin Yahya al-Ghassani said: I came to Madinah and met Abu Bakr bin Muhammad bin Amr bin Hazm (may Allah have mercy on him), who was the governor of Madinah in those days. He said: A thief from your land was brought to me; he had committed a petty theft. My maternal aunt Amrah bint Abd al-Rahman (may Allah have mercy on her) sent me this message: Do not be hasty in deciding the matter of this thief until I come to you; I will tell you what I heard from Aishah (may Allah be pleased with her) about theft. He said: Then she came to me and said: Aishah (may Allah be pleased with her) used to say that the Messenger of Allah (peace and blessings be upon him) said: "Cut off the thief's hand for property equal to a quarter of a dinar, and do not cut off the hand for less than that."
In those days a quarter of a dinar was equal to three dirhams, and one dinar was equal to twelve dirhams. The theft this thief had committed was worth less than a quarter of a dinar, so I did not cut off his hand.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السرقة / 17164