How to run SQL query with a update statement, where clause and order by/

Can someone please help I keep on getting this error: The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions unless TOP, OFFSET or FOR XML is also specified. This is the query I'm using:

UPDATE  SMS 
SET idx30 = 'New' 
WHERE idx30 in (SELECT * 
    FROM SMS 
    WHERE
    idx30 IS NULL
    AND 
    (idx15 = 'Del' OR idx15 = 'Fail')
    AND 
    Idx13 <> '1'
    AND
    Idx7 >= DATEADD(day, -1, GETDATE()) 
    ORDER BY idx7 DESC);