The verse: "And say to the believing women that they should lower gaze was partly abrogated by the verse: "Such elderly women as are past the prospect of marriage."  

عَنِ ابْنِ عَبَّاسٍ { وَقُلْ لِلْمُؤْمِنَاتِ يَغْضُضْنَ مِنْ أَبْصَارِهِنَّ } الآيَةَ فَنُسِخَ وَاسْتُثْنِيَ مِنْ ذَلِكَ { وَالْقَوَاعِدُ مِنَ النِّسَاءِ اللاَّتِي لاَ يَرْجُونَ نِكَاحًا } الآيَةَ  

I was with the Messenger of Allah ﷺ while Maymunah was with him. Then Ibn Umm Maktum came. This happened when we were ordered to observe veil (purdah). The Prophet ﷺ said: Observe veil from him. We asked: Messenger of Allah! is he not blind? He can neither see us nor recognise us. The Prophet ﷺ said: Are both of you blind? Do you not see him? AbuDawud said: This was peculiar to the wives of the Prophet ﷺ. Do you not see that Fatimah daughter of Qays passed her waiting period with Ibn Umm Maktum. The Prophet ﷺ said to Fatimah daughter of Qays: Pass your waiting period with Ibn Umm Maktum, for he is a blind man. You can put off your clothes with him.  

كُنْتُ عِنْدَ رَسُولِ اللَّهِ ﷺ وَعِنْدَهُ مَيْمُونَةُ فَأَقْبَلَ ابْنُ أُمِّ مَكْتُومٍ وَذَلِكَ بَعْدَ أَنْ أُمِرْنَا بِالْحِجَابِ فَقَالَ النَّبِيُّ ﷺ احْتَجِبَا مِنْهُ فَقُلْنَا يَا رَسُولَ اللَّهِ أَلَيْسَ أَعْمَى لاَ يُبْصِرُنَا وَلاَ يَعْرِفُنَا فَقَالَ النَّبِيُّ ﷺ أَفَعَمْيَاوَانِ أَنْتُمَا أَلَسْتُمَا تُبْصِرَانِهِ  

On his father's authority, said that his grandfather reported the Prophet ﷺ said: When one of you marries his male-slave to his slave-woman, he should not look at her private parts.  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا زَوَّجَ أَحَدُكُمْ عَبْدَهُ أَمَتَهُ فَلاَ يَنْظُرْ إِلَى عَوْرَتِهَا  

On his father's authority, said that his grandfather reported the Prophet ﷺ said: When one of you marries his female servant to his slave or to his employee, he should not look at her private part below the navel and above the knees. Abu Dawud said: The correct name is Sawwad b. Dawud al-Muzani al-Sairafi (and not Dawud b. Sawwad as mentioned in the chain). The narrator waki' misunderstood it.  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا زَوَّجَ أَحَدُكُمْ خَادِمَهُ عَبْدَهُ أَوْ أَجِيرَهُ فَلاَ يَنْظُرْ إِلَى مَا دُونَ السُّرَّةِ وَفَوْقَ الرُّكْبَةِ