Is there a Hadith encouraging us to write knowledge down when we study?

Yes, there is a weak Hadith encouraging us to write knowledge down when we study.

حَدَّثَنَا أَبُو بَكْرِ بْنُ إِسْحَاقَ، أَنْبَأَ مُحَمَّدُ بْنُ شَاذَانَ الْجَوْهَرِيُّ، وَأَخْبَرَنِي أَحْمَدُ بْنُ سَهْلٍ الْفَقِيهُ، بِبُخَارَى، ثنا صَالِحُ بْنُ مُحَمَّدِ بْنِ حَبِيبٍ، قَالَا: ثنا سَعِيدُ بْنُ سُلَيْمَانَ الْوَاسِطِيُّ، ثنا عَبْدُ اللَّهِ بْنُ الْمُؤَمَّلِ، حَدَّثَنَا ابْنُ جُرَيْجٍ، عَنْ عَطَاءٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرِو بْنِ الْعَاصِ، قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «قَيِّدُوا الْعِلْمَ» قُلْتُ: وَمَا تَقْيِيدُهُ؟ قَالَ: «كِتَابَتُهُ». التعليق من تلخيص الذهبي: ابن المؤمل ضعيف

Abdullah bin Amr bin al-Aas (May Allah Most High be pleased with them both) said that the Messenger of Allah (Peace be upon him) said, ‘Capture knowledge.’ I said, how is it captured? He (peace be upon him) said, ‘By writing it.’ (al-Mustadrak, Hakim 362).

In the Hadith above the Holy Prophet (peace be upon him) is encouraging us to write down the knowledge we study in order to preserve it. The narration is weak, as mentioned by Imam al-Dhahabi in his Ta’leeqaat on the Mustadrak.

It is important to note that weak Hadith can be used for Nafl issues. Unfortunately, some people have gone to an extreme and reject weak Hadith outright, such an approach contradicts the methodology of the Imams of Hadith.

وَمَنْ نُقِلَ عَنْهُ ذَلِكَ: ابْنُ حَنْبَلٍ، وَابْنُ مَهْدِيٍّ، وَابْنُ الْمُبَارَكِ، قَالُوا: إِذَا رُوِّينَا فِي الْحَلَالِ وَالْحَرَامِ شَدَّدْنَا، وَإِذَا رُوِّينَا فِي الْفَضَائِلِ وَنَحْوِهَا تَسَاهَلْنَا

تَنْبِيهٌ: لَمْ يَذْكُرِ ابْنُ الصَّلَاحِ وَالْمُصَنِّفُ هُنَا، وَفِي سَائِرِ كُتُبِهِ لِمَا ذُكِرَ سِوَى هَذَا الشَّرْطِ، وَهُوَ كَوْنُهُ فِي الْفَضَائِلِ وَنَحْوِهَا، وَذَكَرَ شَيْخُ الْإِسْلَامِ لَهُ ثَلَاثَةَ شُرُوطٍ

أَحَدُهَا: أَنْ يَكُونَ الضَّعْفُ غَيْرَ شَدِيدٍ، فَيَخْرُجُ مَنِ انْفَرَدَ مِنَ الْكَذَّابِينَ وَالْمُتَّهَمِينَ بِالْكَذِبِ، وَمَنْ فَحُشَ غَلَطُهُ، نَقَلَ الْعَلَائِيُّ الِاتِّفَاقَ عَلَيْهِ

الثَّانِي: أَنْ يَنْدَرِجَ تَحْتَ أَصْلٍ مَعْمُولٍ بِهِ

الثَّالِثُ: أَنْ لَا يُعْتَقَدَ عِنْدَ الْعَمَلِ بِهِ ثُبُوتُهُ، بَلْ يُعْتَقَدُ الِاحْتِيَاطُ

It has been narrated from Ibn Hanbal, Ibn Mahdi, Ibn Mubarak, who all said, if Hadith regarding Halal and Haram are narrated then we are strict. And if Hadith regarding the virtues of deeds and the like are narrated then we are lenient.

Important Note: Ibn Salaah and the author did not mention here or in any of their books, any conditions except for this one. Namely, it (the weak Hadith) being used for the virtues of deeds. Shaykh al-Islam mentioned three conditions for it:

Firstly, the weakness cannot be severe, this excludes narrations that have liars in them, or narrations of those accused of lying, and those who make grave errors when narrating,  al-Alai narrated agreement upon this condition. 

Secondly, it must be in line with an established acted upon teaching (of the Deen). 

Thirdly, when acting upon it (the weak Hadith) one cannot believe it to be a sound narration, rather one must keep in mind caution. (Imam al-Sayuti, Tadreeb al-Rawi volume 1 page 351 Dar Taybah). 

And Allah Most High Knows Best.

– Answered by Shaykh Noorud-deen Rashid (11.01.2022)

See also:

Is it permitted to use weak Hadith for Nafl action?

Using Weak Hadith

What do the different Hadith classification terms mean?

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