A woman made a sign from behind a curtain to indicate that she had a letter for the Messenger of Allah ﷺ. The Prophet ﷺ closed his hand, saying: I do not know this is a man's or a woman's hand. She said: No, a woman. He said: If you were a woman, you would make a difference to your nails, meaning with henna.  

أَوْمَتِ امْرَأَةٌ مِنْ وَرَاءِ سِتْرٍ بِيَدِهَا كِتَابٌ إِلَى رَسُولِ اللَّهِ ﷺ فَقَبَضَ النَّبِيُّ ﷺ يَدَهُ فَقَالَ مَا أَدْرِي أَيَدُ رَجُلٍ أَمْ يَدُ امْرَأَةٍ قَالَتْ بَلِ امْرَأَةٌ قَالَ لَوْ كُنْتِ امْرَأَةً لَغَيَّرْتِ أَظْفَارَكِ يَعْنِي بِالْحِنَّاءِ  

A woman made a sign from behind a curtain to indicate that she had a letter for the Messenger of Allah ﷺ. The Prophet ﷺ closed his hand, saying: I do not know this is a man's or a woman's hand. She said: No, a woman. He said: If you were a woman, you would make a difference to your nails, meaning with henna. (Using translation from Abū Dāʾūd 4166)   

مَدَّتْ امْرَأَةٌ مِنْ وَرَاءِ السِّتْرِ بِيَدِهَا كِتَابًا إِلَى رَسُولِ اللهِ ﷺ فَقَبَضَ النَّبِيُّ ﷺ يَدَهُ وَقَالَ مَا أَدْرِي أَيَدُ رَجُلٍ أَوْ يَدُ امْرَأَةٍ؟ فَقَالَتْ بَلْ امْرَأَةٌ فَقَالَ لَوْ كُنْتِ امْرَأَةً غَيَّرْتِ أَظْفَارَكِ بِالْحِنَّاءِ  

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»