Shaykh Albaani, may Allaah have mercy upon him, said
The Scholars have said (that) from the signs that one is blessed in his knowledge is him referring points of benefits to the founder of it” (such as the author or the translator or a reference to where one got the benefit from), because in doing that one frees himself from plagiarism as it is been brought to attention by the Prophet, alaihi as salaatu wa salaam, in his statement: The one being satisfied with that he has not been given is as a person wearing two garments of deception. Agreed upon by al Bukaari and Muslim.
The Reference: The Preface of Shaykh Albaani for the Book: kalimut tayyib for Shaykul Islaam bin Taymiyah.
Translated by
AbdulFattaah Bin Uthman
Abu Fajr