Answered by Ustadh Tabraze Azam
Question: There is a Hadith narrated by Ibn-Abbas that the Prophet(SAW) said there are three things which are obligatory (Fard) on me but optional (Nafl) for my ummah. These are:
 Two rakat fajar sunnah prayers
 Witr prayer(in Isha)
 Animal Sacrifice.
Please clarify this point, and how far this hadith is authentic.
Answer: Assalamu alaikum wa rahmatullahi wa barakatuh,
I pray that you are well, insha’Allah.
Ibn Abbas relates that he heard the Messenger of Allah (Allah bless him and give him peace) say, “Three things are obligatory upon me, and optional for you: the witr prayer, sacrifice and the duha prayer.” [Musnad Ahmad]
The chain of transmission for this narration is weak; as verified by Shaykh Shu`ayb Arna`ut, and understood from Ibn Hajar’s comments in his Talkhis al-Habir.
And Allah knows best.
Checked & Approved by Faraz Rabbani