"We used to fast on 'Ashura and give Zakatul-Fitr, and when the command to fast in Ramadan was revealed, and the command to give Zakah was revealed, we were neither commanded to give it, nor told not to do so, and we used to do it." (Using translation from Nasāʾī 2506)  

«كُنَّا نَصُومُ عَاشُورَاءَ وَنُؤَدِّي صَدَقَةَ الْفِطْرِ فَلَمَّا نَزَلَ رَمَضَانُ وَنَزَلَتِ الزَّكَاةُ لَمْ نُؤْمَرْ بِهِ وَلَمْ نُنْهَ عَنْهُ وَكُنَّا نَفْعَلُهُ»  

"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. (Using translation from Nasāʾī 2507)   

«أَمَرَنَا رَسُولُ اللهِ ﷺ بِصَدَقَةِ الْفِطْرِ قَبْلَ أَنْ تَنْزِلَ الزَّكَاةُ فَلَمَّا نَزَلَتِ الزَّكَاةُ لَمْ يَأْمُرْنَا وَلَمْ يَنْهَنَا وَنَحْنُ نَفْعَلُهُ» قَالَ أَبُو عَبْدِ الرَّحْمَنِ أَبُو عَمَّارٍ هَذَا اسْمُهُ عَرِيبُ بْنُ حُمَيْدٍ وَعَمْرُو بْنُ شُرَحْبِيلَ كُنْيَتُهُ أَبُو مَيْسَرَةَ