Sayyiduna Muslim bin Abd al-Rahman (may Allah be pleased with him) said: I saw the Messenger of Allah (peace and blessings be upon him) taking the pledge of allegiance from the women on al-Safa in the year of the Conquest of Makkah. Meanwhile a woman came whose hand was like the hand of a man, and he (peace and blessings be upon him) refused to take her pledge until she went and coloured her hand with yellow dye. And a man came to him (peace and blessings be upon him) with an iron ring on his hand, and he (peace and blessings be upon him) said: "Allah does not purify a palm on which there is an iron ring."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17103