Sheikhul Islam Muhammad bin Abdul Wahhab mentions the evidence for the four matters:
بسم الله الرحمن الرحيم * وَالْعَصْرِ * إِنَّ الْإِنسَانَ لَفِي خُسْرٍ * إِلَّا الَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ وَتَوَاصَوْا بِالْحَقِّ وَتَوَاصَوْا بِالصَّبْرِ
Meaning: “By time, Indeed, mankind is in loss, Except for those who have Iman (believed) and done righteous deeds and advised each other to truth and advised each other to patience.”
(Quran: Surah Al-Asr)
Here in this Ayat it is made clear that all of mankind, all of them are in loss, except for those who have the four qualities. So it is clear that attaining these four qualities is a Fard Ayn on every single Mukallaf and none is exempted.
- “Except for those who have Iman (believed)” is proof for Ilm (knowledge) because it is impossible to have Iman in something which he has no knowledge off.
- “and done righteous deeds” is proof for action upon the knowledge.
- “and advised each other to truth” is proof for Dawah.
- “and advised each other to patience” is proof for patience infront of the difficulties faced.
So this Surah contains proof for the obligation of the four matters mentioned by the Sheikh, as all of mankind is in loss except those who have these four qualities. And this proves the obligation of these four matters.
WORDS OF IMAM AL-SHAFI’EE:
And then the Sheikh mentions the words of Imam al-Shafi’ee Rahimahullah:
“لو ما أنزل الله حجة على خلقه إلا هذه السورة لكفتهم”
Meaning: “Had Allah not send down any Hujjah upon the creation except this Surah, it would have sufficed them.”
He is Muhammad bin Idris al-Shafi’ee and is an Imam of one of the four famous Mazhabs. His words mean that this Surah summarizes the correct Manhaj inorder to be saved from the Fire and entered to Paradise, not that this Surah is enough for the entire Shariah.
WORDS OF IMAM AL-BUKHARI:
And then the Sheikh mentions the words of Imam al-Bukhari Rahimahullah:
بابٌ: العلم قبل القول والعمل. والدليل قوله تعالى: “فَاعْلَمْ أَنَّهُ لَا إِلَٰهَ إِلَّا اللَّهُ وَاسْتَغْفِرْ لِذَنبِكَ” فبدأ بالعلم قبل القول والعمل
Meaning: “Chapter: al-Ilm (knowledge) precedes words and actions.” And the evidence is the statement of Allah:
فَاعْلَمْ أَنَّهُ لَا إِلَٰهَ إِلَّا اللَّهُ وَاسْتَغْفِرْ لِذَنبِكَ
“So know, [O Muhammad], that there is no deity except Allah and ask forgiveness for your sin”
So He started with knowledge before words and actions. He is al-Imam Muhammad bin Ismail al Bukhari, the author of Sahih al-Jami’ and other beneficial books.
The point here is that action should be based upon knowledge, else it would be exhaustion and harm upon the doer.
This is the end of the commentary on the first introduction of al-Usul al-Thalatha of Sheikhul Islam Muhammad bin Abdul Wahhab Rahimahullah.
وصلى الله على سيدنا محمد وعلى آله وصحبه وسلم
 Famous as Sahih al-Bukhari
Audio in Urdu: Dr. Farhat Hashmi – Al-Usul al-Thalathah
Arabic Text: Download Book-Al-Usul Al-Thalaathah