problem with WHERE clause matching on Arabic string

Try adding N before the text e.g.

select * from table_name
where name=N'arabic_text'

If you search for word احمد and your records have أحمد your query will return nothing even if you are using like '%احمد%' . It is better to use Full-Text search.

DECLARE @SearchWord nvarchar(100)
SET @SearchWord = 'احمد'

DECLARE @SearchString nvarchar(100)
SET @SearchString = 'FormsOf(INFLECTIONAL, "' + @SearchWord + '")' 
--SET @SearchString =  @SearchWord 

SELECT Ar.[SuraID]
      ,Ar.[VerseID]
      ,Ar.[AyahText] as Arabic
      ,En.[AyahText] as English
  FROM [QuranDb].[dbo].[ArabicQuran] Ar
  join EnglishQuran En on En.ID=Ar.ID
  where   CONTAINS(ar.AyahText, @SearchString) 
 or  CONTAINS(En.AyahText, @SearchString ) 
Query with Full-Text (Inflectional) enter image description here

Here is other example using CONTAINSTABLE CONTAINSTABLE link

DECLARE @SearchWord nvarchar(100)
SET @SearchWord = 'لا اله الا الله '

DECLARE @SearchString nvarchar(100)
SET @SearchString ='ISABOUT ("'+ @SearchWord+'")' 

SELECT K.RANK, Ar.AyahText,Ya.AyahText
FROM [ArabicQuran] AS Ar  
  INNER JOIN  
  CONTAINSTABLE([ArabicQuran], AyahText, @SearchString, LANGUAGE N'arabic'  ) AS K  
  ON Ar.ID = K.[KEY] 
  join EnQuranYusufAli Ya on ya.ID=Ar.ID
  order by k.RANK desc 

select * from table_name
where name like N'%arabic_text%' 

will work here