One can see how Salafis have an inordinate obsession with authentic chains of narrations and have this arrogant claim that they strictly adhere to this principle.
In the article "The Role of Isnad in the Preservation of the Islamic Civilisation" We read:
The Islamic ideology derives from the Qur’an and Sunnah. Legislation in Islam also derived from these two sources. Therefore if any one of these sources is lost or distorted then the risk is to the ideology as a whole. In this respect the study of Isnad is not a peripheral discipline in Islam but fundamental to the preservation of the ideology itself. Without Isnad the Sunnah as a source of ahkam would cease to exist. Without Isnad we would lose the ability to elaborate, specify and restrict the ambivalent, general and absolute import of the Quranic text since the role of the Sunnah is to clarify the Qur’an. Without Isnad, extraction of Sharee’ah rules for new realities from the Sunnah would cease to exist. Without Isnad foreign elements could have been incorporated within the ideology due to their false attribution to the Prophet (saw). Thus, Isnad is crucial for the purity, clarity and crystallization of the Islamic ideology and its ability to solve new problems from its legislative source. That is why ‘Abdullah b. Mubarak the teacher of Imam al-Bukhari (Rahmatullahi ‘alayhim) did not exaggerate when he said:
"The isnad is part of the Deen: had it not been for the isnad, whoever wished to would have said whatever he liked.’
http://islamicsystem.blogspot.com/.../role-of-isnad-in...
Abdullah b. Mubarak might well have believed that "isnad is part of the Deen" but when it comes to accepting a false narration according to their own whims, then all the principles are placed on the back burner. They have taken narrations from persons unknown as can be evidenced from their most authentic book, Sahih Bukhari in the Book "Virtues and Merits of the Prophet (s) and his Companions":
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، أَخْبَرَنَا سُفْيَانُ، حَدَّثَنَا شَبِيبُ بْنُ غَرْقَدَةَ، قَالَ سَمِعْتُ الْحَىَّ، يُحَدِّثُونَ عَنْ عُرْوَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم أَعْطَاهُ دِينَارًا يَشْتَرِي بِهِ شَاةً، فَاشْتَرَى لَهُ بِهِ شَاتَيْنِ، فَبَاعَ إِحْدَاهُمَا بِدِينَارٍ وَجَاءَهُ بِدِينَارٍ وَشَاةٍ، فَدَعَا لَهُ بِالْبَرَكَةِ فِي بَيْعِهِ، وَكَانَ لَوِ اشْتَرَى التُّرَابَ لَرَبِحَ فِيهِ. قَالَ سُفْيَانُ كَانَ الْحَسَنُ بْنُ عُمَارَةَ جَاءَنَا بِهَذَا الْحَدِيثِ عَنْهُ، قَالَ سَمِعَهُ شَبِيبٌ مِنْ عُرْوَةَ، فَأَتَيْتُهُ فَقَالَ شَبِيبٌ إِنِّي لَمْ أَسْمَعْهُ مِنْ عُرْوَةَ، قَالَ سَمِعْتُ الْحَىَّ يُخْبِرُونَهُ عَنْهُ. وَلَكِنْ سَمِعْتُهُ يَقُولُ سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " الْخَيْرُ مَعْقُودٌ بِنَوَاصِي الْخَيْلِ إِلَى يَوْمِ الْقِيَامَةِ ". قَالَ وَقَدْ رَأَيْتُ فِي دَارِهِ سَبْعِينَ فَرَسًا. قَالَ سُفْيَانُ يَشْتَرِي لَهُ شَاةً كَأَنَّهَا أُضْحِيَّةٌ.
Narrated `Urwa:
That the Prophet (ﷺ) gave him one Dinar so as to buy a sheep for him. `Urwa bought two sheep for him with the money. Then he sold one of the sheep for one Dinar, and brought one Dinar and a sheep to the Prophet. On that, the Prophet (ﷺ) invoked Allah to bless him in his deals. So `Urwa used to gain (from any deal) even if he bought dust. (In another narration) `Urwa said, "I heard Allah's Messenger (ﷺ) saying, "There is always goodness in horses till the Day of Resurrection." (The subnarrator added, "I saw 70 horses in `Urwa's house.') (Sufyan said, "The Prophet (ﷺ) asked `Urwa to buy a sheep for him as a sacrifice.")
(Sunni source: Sahih Bukhari Book 61, Hadith 146)
On the facts of it everything appears fine BUT that's on account of the dishonesty of the English translation.
The last few lines have not been translated, namely the admission of Shabib bin Gharqada:
"I came across Shabib he says didn't hear this Hadith from Urwa, rather I heard it from the people from my tribe"
۔ چنانچہ میں شبیب کی خدمت میں گیا تو انہوں نے بتایا کہ *میں نے یہ حدیث خود عروہ سے نہیں سنی تھی۔ البتہ میں نے اپنے قبیلہ کے لوگوں کو ان کے حوالے سے بیان کرتے سنا تھا*۔
Clearly the English translator Dr Muhsin Khan realised the implications of this and knowingly omitted these words as it renders the entire narration otiose. Who were the tribesman that narrated this to Shabib? Were they Muslims, hypocrites, Jews, adherents of Abdullah ibn Saba? Obviously, we, have no means of ascertaining this, the narration had been taken from unknown people, and just goes to show the Ahlul Sunnah grading of Hadith is a total farce. Herein appears a narration from unknown narrators graded as Sahih in a Book the Ahul Sunnah insist is impeccable, with every chain authentic.