Narrated Abud Darda: The Prophet ﷺ said: The intercession of a martyr will be accepted for seventy members of his family. Abu Dawud said: The correct name if the narrator is Rabah bin al-Walid (and not al-walid bin Rabah as occurred in the chain of narrators in the text of the tradition)
Hadith Referenceسنن ابي داود / كتاب الجهاد / 2522
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:حسن, وله شاھد عند الترمذي (1663) وابن ماجه (2799 وسنده حسن)
Benefits and Issues: This narration is authentic according to Shaykh al-Albani. In order to be deserving of this intercession, it is extremely necessary to possess the creed of Tawheed (monotheism) and the Sunnah. Because there is absolutely no forgiveness for a polytheist (mushrik). And Paradise is forbidden for him. The statement of Allah, the Exalted, is: ﴿إِنَّاللَّـهَلَايَغْفِرُأَنيُشْرَكَبِهِوَيَغْفِرُمَادُونَذَٰلِكَلِمَنيَشَاءُ﴾ (an-Nisa: 48) — Verily, Allah does not forgive that partners should be associated with Him, but He forgives whatever is less than that for whomsoever He wills. And in another place He said: ﴿اِنَّهُمَنيُشْرِكْبِاللَّـهِفَقَدْحَرَّمَاللَّـهُعَلَيْهِالْجَنَّةَوَمَأْوَاهُالنَّارُ﴾ (al-Ma'idah: 72) — Verily, whoever associates partners with Allah, then indeed Allah has forbidden Paradise for him, and his abode is the Fire.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 2522