If the shirt includes writing that is not prohibited but it attracts attention and distracts the worshippers who look at it, then it is disliked to pray in it in that case, otherwise it is not disliked. But if the writing carries prohibited meanings, it is not permissible to wear it at all, whether outside the prayer or when praying.

Just as it is not permissible for a Muslim man to wear natural silk, it is also not permissible for him to sit or sleep on it or to cover himself in it like a blanket.