From Tar Valon Library
Author: Kyria d'Oreyn
He is on duty at the main gates. Mat, with a letter for Morgase from Elayne, walks up to him and wants to enter the Royal Palace as a messenger from the White Tower. Elber does not believe that he is from Tar Valon and tells him furthermore that Morgase will take not letters from the Tower until they return Elayne to her (TDR, Ch. 45).
Tallanvor escorts Mat outside once he has delivered Elayne’s letter and berates Elber for not letting him in (TDR, Ch. 47).
"A fat man with eyes like a rat?" Mat cursed his tongue, but the officer gave a sharp nod; he almost smiled, too, but it did not seem to lessen his vigilance, or his suspicion. "He grew angry when he learned I had come from Tar Valon, and he wouldn't even give me a chance to show the letter or mention the Daughter-Heir's name. He said he would arrest me if I did not go, so I climbed the wall." (Mat and Tallanvor on Elber; The Dragon Reborn, Chapter 46)