Shaykh Albaani, may Allaah have mercy upon him, said:
The Scholars have said:
“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 a reference to where one got the benefit from)
Because in doing that one frees himself from plagiarism as it has been brought to attention by the Prophet, alaihi as salaatu wa salaam, in his statement:
“The one being satisfied with that which he has not been given is as a person wearing two garments of deception”.
Agreed upon by al Bukaari and Muslim.
The Preface of Shaykh Albaani for the Book: Kalimut Tayyib for Shaykul Islaam ibn Taymiyah