Yes, the Hadith ‘There is no Safar’ is authentic.’ It is in Sahih al-Bukhari and Sahih Muslim. The scholars agree that all Musnad Hadith in Sahih Bukhari and Sahih Muslim are authentic.
أَنَّ أَبَا هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ، قَالَ: إِنَّ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ: «لاَ عَدْوَى وَلاَ صَفَرَ وَلاَ هَامَةَ»
Abu Hurairah said that Allah’s Messenger ﷺ said, ‘There is no (independently) transmissible (disease), no Safar and no Haamah.’ (Sahih al-Bukhari, 5717).
The Hadith, There is no Safar, is repeated in Sahih al-Bukhari and Sahih Muslim many times. All Musnad narrations in Bukhari and Muslim are certainly Sahih. So even if there was a single narration of this Hadith in either collection it would be Sahih. The fact that it is repeated many times with varying chains only serves to strengthening it further.
جَمِيع مَا حكم مُسلم بِصِحَّتِهِ من هَذَا الْكتاب فَهُوَ مَقْطُوع بِصِحَّتِهِ وَالْعلم النظري حَاصِل بِصِحَّتِهِ فِي نفس الْأَمر وَهَكَذَا مَا حكم البُخَارِيّ بِصِحَّتِهِ فِي كِتَابه وَذَلِكَ لِأَن الْأمة تلقت ذَلِك بِالْقبُولِ سوى من لَا يعْتد بِخِلَافِهِ ووفاقه فِي الْإِجْمَاع (صيانة صحيح مسلم)
Everything that (Imam) Muslim considered to be Sahih of this book is undoubtedly Sahih, and it leads to contemplative certainty due to its authenticity. Likewise, everything that (Imam) al-Bukhari considered to be Sahih in his book (is Sahih), because the Ummah has accepted that reality (the authenticity of Bukhari and Muslim) with agreement. With the exception of a few, whose acceptance or disagreement does not affect the consensus. (Imam Ibn Salah, Siyanatu Sahih Muslim).
It is important for Muslims to learn the basics of Hadith science (Uloom al-Hadith). Since we regularly encounter Hadith and many Muslims forward them to others, it is essential to have some understanding regarding Hadith authenticity when engaging with Hadith.
– Answered by Shaykh Noorud-deen Rashid (15.09.2021)
Is the month of Safar bad omen or bad luck?
Are all Hadith in Bukhari and Muslim Sahih?
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