Musnad Abu Ya'la al-Mawsili 105:48

Muhammad ibn ‘Ammar narrated to us, ‘Abd al-Wahhab narrated to us, ‘Ubayd Allah narrated to us, from Sa‘id ibn Abi Sa‘id, from ‘Umar ibn Abi Bakr ibn ‘Abd al-Rahman ibn al-Harith ibn Hisham, that ‘Ammar ibn Yasir entered the mosque and prayed two light rak‘ahs. A man said, "You made them light, O Abu al-Yaqzan." He replied, "Did you see me omit anything of their limits? I hastened through them to avoid the whisperings (of Satan). I heard the Messenger of Allah (ﷺ) say: 'Indeed, a man may pray, and perhaps there is nothing for him from his prayer except a tenth of it, or a ninth of it, or an eighth of it, or a seventh of it, or a sixth of it, or a fifth of it, or a fourth of it, or a third of it, or half of it.'"