Shaykh Muhammad Ibn Hizaam was asked:
Has a narration been affirmed in regards to Salatut Tasaabeeh?
There is no narration affirmed in regards to that, the best of that which is reported in this chapter is the narration of Ibn Abbas, [which] our Shaykh Muqbil may Allah have mercy upon him relayed it in Saheeh Al Musnad and it is in the beginning of Musnad Ibn Abbas for the one who wishes to read it.
Then the Shaykh was pleased with declaring it defective, a research was read to him in declaring it defective, Ibn Al Madeeni, Ath Thahabi and other than them from the scholars declared it defective.
Thus the Shaykh was pleased with that, and Allah knows best why it wasn’t erased [from Musnad Ahmad with us wondering] did the Shaykh forget to erase it or the paper in which it was clarified was lost or similar to that.
In any situation, it wasn’t erased from As Saheeh Al Musnad, but the Shaykh himself returned from declaring it authentic.
Majid Jawed Al Afghanee