عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَجُلًا أَتَى النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ بِجَارِيَةٍ سَوْدَاءَ أَعْجَمِيَّةٍ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّ عَلَيَّ عِتْقَ رَقَبَةٍ مُؤْمِنَةٍ فَقَالَ لَهَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَيْنَ اللَّهُ فَأَشَارَتْ إِلَى السَّمَاءِ بِإِصْبَعِهَا السَّبَّابَةِ فَقَالَ لَهَا مَنْ أَنَا فَأَشَارَتْ بِإِصْبَعِهَا إِلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ وَإِلَى السَّمَاءِ أَيْ أَنْتَ رَسُولُ اللَّهِ فَقَالَ أَعْتِقْهَا
It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that a man brought a black non-Arab slave girl to the Noble Prophet (peace and blessings be upon him) and said: O Messenger of Allah! I have to free a believing slave. The Messenger of Allah (peace and blessings be upon him) asked her: Where is Allah? She pointed towards the sky with her index finger. He (peace and blessings be upon him) then asked: And who am I? She first pointed towards him (peace and blessings be upon him) and then towards the sky. In fact, she wanted to say that you are the Messenger of Allah. The Prophet (peace and blessings be upon him) said: Free her.