أحسن الله إليكم شيخنا Is it permissible to put little posters on walls with ahadith and reminders which might get dirty and so on? جزاك الله خيراً

A lot of people do this as decoration, and This is not allowed. As for if it is a learning aid or something like that that you want to have for a while until you memorize certain hadith or so, then take care of it and do not neglect it. How would you neglect it if you are actually paying attention to it and learning from it? All in all, be careful about using the words of Allah and the Messenger (sallallahu alaihi wasallam) as decorations or something that can be taken lightly.