Ash-Shaykh Yahya al-Hajooree, may Allah preserve him, was asked:
Is it permissible to translate the books of the people of innovations if it is known to be beneficial in its science, (even though) after (translating it) he does not mention the name of the author?
al-Imaam Ibn Qudaamah, may Allah have mercy upon him, mentioned in his book lum’atul I’tiqaad: that it is from the Sunnah to boycott Ahlul bid’a and to disconnect oneself from them, to leave off debating and arguing (with them of issues) of the religion and to leave off looking in their books. Every newly invented matter in the religion is an act of innovation. The meaning of that is that reading the books of misguidance and cooperating in distributing misguidance to the people either by buying, selling, and translations or other than that, all of that is from cooperating upon sin and transgression that which Allah azza wa jall, has prohibited by his statement:
وَتَعَاوَنُوا عَلَى الْبِرِّ وَالتَّقْوَى وَلا تَعَاوَنُوا عَلَى الإِثْمِ وَالْعُدْوَانِ
“Help one another in Al Birr and At Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression.”
And that which could be found of benefit therein, (then) it is possible to come across it in the books of Ahlus Sunnah for verily with in it is much good, and all praise due to Allah.