\documentclass[a4paper]{book}
\usepackage{xepersian}
\settextfont[Scale=1.15]{Yas}
\defpersianfont\nastaliq[Scale=2]{IranNastaliq}
\setdigitfont[Scale=1.15]{Yas}
\begin{document}
\chapter{فصل }
\section{بخش\LTRfootnote{Section}}
متن  

\end{document}