Also, maybe the treaty with the Finns says so. I mean the treaty between the Finns and Aes Sedai

What evidence do we have that Shadow questions are punished? How did Moiraine know they are? I think she just believed it to be true without much evidence. If people came out mad' date=' or not at all, then how does Moiraine know they asked Shadow Questions, or that the Shadow questions were what caused what happened to happen?[/quote']

 

The Tear doorway was in use as recently as a few hundred years ago by the Firsts of Mayene and has been studied fairly extensively by Aes Sedai and Moiraine has read the notes. It's in either The Dragon Reborn or The Shadow Rising when she's telling Egwene, Elayne and Nynaeve about it. She doesn't know from her own experience but she has no reason to think the Rhuidean door would be any different and wouldn't take the chance.