The chain of narration is the weapon of the believer
Sufyaan ath-Thawree 161 AH (May Allah have mercy on him) said: الاسناد سلاح المؤمن, فاذا لم يكن معه سلاح فبأي شيء يقاتل؟ “The isnaad is the weapon of the believer. So if he does not have a weapon then what will he fight with?” Collected by Ibn Hibban in his book “al-Majruhin” (1/27)