Assalaamu alaykum Shaykhs. How authentic are the hadiths that have been reported by Abu-dawud and Musnad Ahmad that say that every hair of the ud-hiyah will be counted, that one will be rewarded for each hair, and that the blood of the ud-hiyah will reach Allaah before it drops on the ground.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger. 

The first hadeeth was narrated by ʻAa'ishah who related that the Prophet, sallallaahu ʻalayhi wa sallam, said, “The son of Aadam (Adam) does not do any deed on the Day of Nahr that is dearer to Allaah than shedding blood. On the Day of Resurrection, its horns, hairs and hoofs will be brought. Its blood is accepted by Allaah before it reaches the ground. So, be content when you do it.” [At-Tirmithi and Ibn Maajah] Al-Albaani declared it saheeh (sound) in his revision of Mishkaat Al-Masaabeeh.

The second hadeeth was narrated on the authority of Zayd ibn Arqam who related that the Companions of the Messenger of Allaah said, “O Messenger of Allaah, what are these Adhaahi (i.e. sacrifices [plural of udh-hiya])?” He said, “It is the Sunnah of your father Ibraaheem (Abraham) .” They said, “What is there for us in them (i.e. rewards), O Messenger of Allaah?” He said, “For every hair, you earn one reward.” They said, “What about the wool, O Messenger of Allaah?” He said, “For every hair of their wool, one reward.” [Ahmad and Ibn Maajah] Al-Albaani declared it weak in his revision of Mishkaat Al-Masaabeeh and later declared it fabricated (i.e. falsely attributed to the Prophet, sallallaahu ʻalayhi wa sallam) in his book As-Silsilah Adh-Dhaʻeefah wal-Mawdhooʻah.

Allaah knows best.