\documentclass[a4paper,11pt]{book}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{xepersian}

\settextfont[Scale=1]{XB Zar}
\setlatintextfont[Scale=1]{Linux Libertine}
\setdigitfont[Scale=1.7]{Times New Roman}


\author{من}
\title{تو}

\begin{document}

\chapter{}

\section{سرآغاز}
\begin{equation}
shfffffffff
\end{equation}

\end{document}