Ibn Seereen says:
"The knowledge of hadith (in the same manner all other religious subjects) are included in the deen. Therefore before acquiring knowledge, be aware from whom knowledge is acquired". (IT)
App reference (IT): Book 56, Hadith 10 (IT)
English reference (IT): Book 55, Hadith 397 (IT)
Arabic reference (IT): Book 56, Hadith 415 (IT)