Is it permissible to take fatwas directly from the ancient books of the Salaf without referring to a trustworthy scholar, and if so, what are the recommended books?

The virtue of the righteous predecessors and the obligation to follow them, and that they are the foundation upon which those who came after them built matters of knowledge.

It is permissible for later scholars who have not reached the rank of ijtihad (independent reasoning) to follow the sayings of the early imams, adopt their ijtihads, and imitate them. The majority of scholars agree on the permissibility of imitating a deceased mujtahid. However, examining the books of the predecessors and early imams and taking rulings and fatwas from them is not accessible to everyone who feels capable of reading them.

So, whoever has a measure of Islamic knowledge and a faculty of understanding that qualifies him to examine them and transmit their fatwas to those below him, then there is no blame upon him. But whoever lacks the scholarly ability and the faculty that qualifies him to examine the books of the predecessors should not transmit from them.

Fatwas are of two types: fatwas of fixed rulings based on evidence, and fatwas that were built upon customs, accompanied by contextual clues, and intertwined with specific events. Such fatwas are to be considered for guidance but their rulings should not be transmitted as they are.

The principle is that it is obligatory for an ordinary person to ask trustworthy scholars of his time. If he cannot find a scholar, it is permissible for him to accept the قول (saying) of someone who transmits the fatwa to him from trustworthy scholars, provided the transmitter is just. It is also permissible for him to examine the fatwas of later scholars and transmit them from them due to the simplicity of their expressions, and by doing so, he is merely a transmitter and conveyor.

Among the beneficial books for transmitting fatwas to non-specialists are: Majmoo' Fatawa al-Lajnah ad-Daa'imah lil-Iftaa (Collection of Fatwas of the Permanent Committee for Issuing Fatwas), Majmoo' Fatawa ash-Shaykh Abd al-Aziz ibn Baz (Collection of Fatwas of Shaykh Abd al-Aziz ibn Baz), and Majmoo' Fatawa wa Rasail ash-Shaykh Ibn Uthaymeen (Collection of Fatwas and Treatises of Shaykh Ibn Uthaymeen).