How to use variables in xpath

Robot Framework
1 
After set varible it shows as p instead of //div[text()='Work Type']/../../div/div/button[@disabled][1] 
   ${xpath}=  //div[text()='Work Type']/../../div/div/button[@disabled]
    ${elements}=  Get WebElements  ${xpath}
    FOR ${row_index} IN RANGE 1 ${elements.__len__()}+1
        ${updated_xpath}=  Set Variable  ${xpath}[${row_index}]
        Log  ${updated_xpath}
        ${text}=  Get Text  ${updated_xpath}
    END

why Afer Set Variable it shows Log output as p instead of //div[text()=‘Work Type’]/…/…/div/div/button[@disabled][1]

2

Looks to be a Duplicate of: