Is speaking about things one does not know properly a sin?Is speaking about things one does not remember correctly a sin?Is speaking about things one does not know at all a sin?

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.

With matters of religion, it is not permissible to speak in terms of providing interpretations or opinions without knowledge and conviction or without believing that it is most likely correct if certainty is not possible.

As for inquiring about a religious interpretation, it is permissible for a person to ask about matters that he does not know about very well, or which he does not know about at all or which he has doubts about.

Indeed, we have already clarified the prohibition and seriousness of giving religious interpretations without knowledge and of engaging in matters of religion without knowledge in Fataawa 145205 and 198821, so please refer to them.

It is also prohibited to engage in a lot of talk about worldly matters based on assumption without verification.

Allaah says (what means): {O you who have believed, if there comes to you a disobedient one with information, investigate, lest you harm a people out of ignorance and become, over what you have done, regretful.} [Quran 49:6]

Abu Hurayrah related that the Prophet said: “Suffice it as a lie that one speaks about everything one hears.” [Muslim]

Shaykh Al-Uthaymeen said in his commentary on this Hadeeth:

“It means that if a person speaks about everything he hears without verifying it, then he is likely to lie, and this is the reality. Some people come to you and say, such a thing has happened, and if you investigate the matter, you find that it did not happen. Or, a person comes to you and says, so and so said such and such, and if you investigate the matter, you find that he did not say it.” [End of quote]

Allaah Knows best.