\documentclass{article}
\usepackage[T1]{fontenc}

\usepackage[explicit]{titlesec}

\titleformat{\section}
    {\normalfont\Large\bfseries} % format: style
    {} % label: number
    {0pt} % sep: horisontal space between number and content
    {a#1b} % before-code: content

\begin{document}

\makeatletter
\meaning\ttlf@section
\makeatother

\end{document}