Salaam Alaikum, Dear Shaikh I have many question kindly reply me in details, What is Daif Hadith? And can one use them (follow its instructions) or tell others for goodness? Is there any famous book that explains about types of Hadith their claasification, forms etc? From my childhood, I have been informed (about Hadith) that the customer should haggle the seller for the price (to make it cheap) until water appears on forehead, kindly provide that Hadith and please tell us whether it is Sahih or not? And is it Bid'ah (innovation) to say "Sadaqaa ALLAHU Al-Azeem" after the completion of Surah? Sorry for so many questions. Jazaak ALLAHU Khair.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

The Dha’eef [inauthentic] Hadeeth is the Hadeeth that does not reach the status of Hasan [sound], i.e. in which the conditions of Hasan Hadeeth are not met. For more information, please refer to Fatwa 86128.

The scholars   differed in opinion as to acting upon the Dha’eef Hadeeth. Many scholars   are of the view that it is permissible to act upon it in regard to virtuous deeds (i.e. to encourage them) with three conditions:

1- The Hadeeth should not be very Dha’eef.

2- It should come under a general principle that is acted upon.

3- When acting upon it, one should not believe that this Hadeeth is confirmed [authentic]; rather, the person should only act upon it out of religious caution. For more benefit, please refer to Fatwa 13202.

Also, it is permissible to narrate a Dha’eef Hadeeth while clarifying that it is Dha’eef. The Muslim scholars used to mention the Dha’eef Hadeeth while mentioning its chain of narration or clarifying its status and they used to say: “Whoever mentions the chain of narrators of the Hadeeth, then he has referred you, meaning he has referred you to knowing the status of this very Hadeeth according to the chain of narrators that he mentioned.”

Among the most important books that shows the rules of Hadeeth and its kinds, is the book entitled “Ikhtisaar ‘Uloom Al-Hadeeth”, authored by Ibn Katheer   and which was explained by Shaykh Ahmad Shaakir   in his book entitled “Al-Baa’ith Al-Hatheeth”; this is a concise book, and there are other extended books like the book entitled “Tadreeb Ar-Raawi” authored by As-Suyooti .

As regards the Hadeeth about haggling (with the seller) which you referred to in the question, then we have not come across it in the reliable books of Hadeeth that we have at hand, and we do not think that there is an authentic Hadeeth with the same meaning. Rather, what is confirmed in authentic Ahaadeeth is the order to be tolerant when buying and selling.

Jaabir   narrated that the Prophet   said: ''May Allaah have mercy upon a man who is tolerant when he buys, when he sells, and when he demands payment." [Al-Bukhari]

As regards a person saying after reciting the Quran: “Allaah, the Great, has told the truth”, then this is a general (unrestricted) mention of Allaah, so for restricting it to a specific time, place, or circumstance, one must have evidence for this, because the restricted Athkaar (forms of legislated mention of Allaah) cannot be recited (regularly on specific occasions) unless there is evidence for it. Therefore, being committed to this wording (form of the mention of Allaah) after the recitation of the Quran has no evidence, and worshipping Allaah with something that is not legislated is not permissible, so this is among the invented matters of religion. For more benefit, please refer to Fatwa 84068.

Allaah Knows best.