Shaikh Salih al-Fawzan (may Allah preserve him) said:
In regards to His statement, the Exalted:
وَالسَّابِقُونَ الْأَوَّلُونَ مِنَ الْمُهَاجِرِينَ وَالْأَنصَارِ وَالَّذِينَ اتَّبَعُوهُم بِإِحْسَانٍ
“And the first to embrace Islam of the Muhajirun (those who migrated from Makkah to Al-Madinah) and the Ansar (the citizens of Al-Madinah who helped and gave aid to the Muhajirun) and also those who followed them exactly (in Faith)” [9:100]
(بِإِحْسَانٍ) means with perfection and not only a claim. So the one who says: “I am Salafi. I am upon the Mathhab of the Salaf”. However if you ask him what the Mathhab of the Salaf is? He says: “I don’t know”.
We say: “You are not Salafi because you don’t know the Mathhab of the Salaf”.
وَالَّذِينَ اتَّبَعُوهُم بِإِحْسَانٍ
And also those who followed them exactly (in Faith)” [9:100]
That is: in knowledge and action and not simply a claim. So learn the Mathhab of the Salaf and what they were upon until you hold fast to it and follow it”.
[al-Ijaabaat al-Faasilah ‘ala ash-Shubuhaat al-Haasilah (pg. 67)]
Faisal bin Abdul Qaadir bin Hassan