Is it permissible to invoke Allah's mercy upon two Sufis who were perhaps Ash'aris, and to mention their good moral qualities, taking into account the widespread prevalence of false and fabricated hadiths during the time of their seeking knowledge?

Every Muslim who outwardly professes Islam, and whose hypocrisy has not been revealed, and against whom proof has not been established, it is permissible to invoke mercy upon him, pray for him, and seek forgiveness for him, even if he has fallen into innovations (bid'ah) or major sins. Indeed, even if his innovations reach the level of disbelief (kufr), not everyone who holds a disbelieving belief becomes an outright disbeliever thereby. Rather, he falls within the general category of Muslims who have previously affirmed their faith, as Ibn Taymiyyah said: "Every Muslim whose hypocrisy is not known, it is permissible to seek forgiveness for him and pray for him, even if he has an innovation or commits فسق (transgression)." Therefore, invoking mercy upon a Muslim is legislated, and praising him for the good within him is not blameworthy.