Possible Clues:

• ''Why? Because ___ so!''
• Words starting a response to 'What?'
• "Let me repeat ... "
• "To reiterate . . ."
• Part of a Neil Diamond title
• "Because __ so!!"
• "In case you didn't hear me ... "
• "In case you didn't hear me ..."
• "To reiterate ... "
• “In case that wasn’t clear...”