Sunan an-Nasa'i 2507
It was narrated that Qais bin Sa'd said:
"The Messenger of Allah commanded us to give Sadaqatul Fitr before the command to give Zakah was revealed. When the command to give Zakah was revealed, he neither told us to do it, not told us not to do it, and we used to do it." (Sahih)
Abu 'Abdur-Rahman (An-Nasai) said: Abu 'Ammar's  name is 'Arib bin Humaid, and 'Amr bin Shurabbil's Kunyah is Abu Maisarah, and Salamah bin Kuhail contradicted Al-Hakam in his chain, and Al-Hakam is more reliable than Salamah bin Kuhail.
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ الْمُبَارَكِ، قَالَ حَدَّثَنَا وَكِيعٌ، عَنْ سُفْيَانَ، عَنْ سَلَمَةَ بْنِ كُهَيْلٍ، عَنِ الْقَاسِمِ بْنِ مُخَيْمِرَةَ، عَنْ أَبِي عَمَّارٍ الْهَمْدَانِيِّ، عَنْ قَيْسِ بْنِ سَعْدٍ، قَالَ أَمَرَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم بِصَدَقَةِ الْفِطْرِ قَبْلَ أَنْ تَنْزِلَ الزَّكَاةُ فَلَمَّا نَزَلَتِ الزَّكَاةُ لَمْ يَأْمُرْنَا وَلَمْ يَنْهَنَا وَنَحْنُ نَفْعَلُهُ ‏.‏ قَالَ أَبُو عَبْدِ الرَّحْمَنِ أَبُو عَمَّارٍ اسْمُهُ عَرِيبُ بْنُ حُمَيْدٍ وَعَمْرُو بْنُ شُرَحْبِيلَ يُكَنَّى أَبَا مَيْسَرَةَ وَسَلَمَةُ بْنُ كُهَيْلٍ خَالَفَ الْحَكَمَ فِي إِسْنَادِهِ وَالْحَكَمُ أَثْبَتُ مِنْ سَلَمَةَ بْنِ كُهَيْلٍ ‏.‏