Abu Dawud Book 2, Hadith Number 1297.
Chapter : Where should the two rakahs of the sunnah prayer of the sunset prayer be offered.
Narated By N/A : Sa’id b. Jubair reported this tradition from the Prophet (PBUH) without mentioning the name of the Companion in the chain (in the mursal form).
Abu Dawud said: I heard Muhammad b. Humaid say: I heard Ya’qub say: Anything I narrated you from Ja’far on the authority of Sa’id b. Jubair from the Prophet (PBUH) is directly from Ibn ‘Abbas from the Prophet (PBUH).