Ibrahim bin Maisarah said that Mujahid saw Tawus (may Allah have mercy on him) in a dream, that he was praying in the Ka'bah with a veil on his face, and the Noble Prophet (peace be upon him) was standing at the door of the Ka'bah and saying: O servant of Allah! Remove your veil, and recite aloud (i.e., narrate the hadith openly). Ibrahim said: He interpreted this as referring to knowledge, and after that, he happily began to narrate hadith.
Hadith Referenceسنن دارمي / مقدمه / 329
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده صحيح غير أنه مرسل، [مكتبه الشامله نمبر: 330]
Hadith Takhrijیہ روایت مرسل ہے، اور [حلية الأولياء 5/4] میں بھی اسی طرح منقول ہے۔