A woman reached out her hand (to give) a letter to the Prophet [SAW], and he withdrew his hand. She said: "O Messenger of Allah, I reached out my hand (to give you) a letter and you did not take it." He said: "I did not know whether it was the hand of a woman or a man." She said: "It is the hand of a woman." He said: "If you were a woman, you would change your nails (by dyeing them with Henna)." (Using translation from Nasāʾī 5089)  

أَنَّ «امْرَأَةً مَدَّتْ يَدَهَا إِلَى النَّبِيِّ ﷺ بِكِتَابٍ فَقَبَضَ يَدَهُ» فَقَالَتْ يَا رَسُولَ اللهِ مَدَدْتُ يَدِي إِلَيْكَ بِكِتَابٍ فَلَمْ تَأْخُذْهُ قَالَ «إِنِّي لَمْ أَدْرِ يَدُ امْرَأَةٍ هِيَ أَمْ يَدُ رَجُلٍ؟» قَالَتْ بَلْ يَدُ امْرَأَةٍ قَالَ «لَوْ كُنْتِ امْرَأَةً لَغَيَّرْتِ أَظْفَارَكِ بِالْحِنَّاءِ»