If you have previously engaged in a drinking contest with Thaler, you have a seemingly useless book, Shadow People, or the story of His Majesty's Secret Service. If you speak to the bootblack a second time, you will notice that you now have the option to give him a gift. Give him the book.
At this point, he says "You know who I am... ahem, I thought that scroll had disappeared for good.", which confirms that he is in fact Ori Reuven. After a bit more conversation, he gives you the Prophet Lebioda's signet ring, which will help Geralt get past Grandma at Shani's place.
Nesrovnalosti s knihou
Protožel měl po válce s Nilgaardem Ori Reuven strávit v různých vězeních 6 let and the game events take place five years after the novel's ending, Ori should technically still be a prisoner and even if he was released he should be more of a human ruin, nowhere near the more or less healthy condition in which Geralt encounters him. (To be fair, his is the same model used for most beggars...)