Religious day of rest (7)
I believe the answer is:
sabbath
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">religious day of rest</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sabbath that I've seen before include "Hebrew word for day of rest" , "Day of rest and worship" , "Traditional holy day" , "Religious day of rest for Jews and Christians" , "Jewish rest-day" .)