Possible Clues:

• 'Hold on a sec,' in texts
• "Hold on a sec," in texts
• 'Gimme a sec,' in chats
• Texter's "Just a sec"
• Palindromic "Hang tight" text
• 'Returning soon,' in texts
• Texter's "Need a short break"
• 'Returning soon,' in online shorthand
• “Just a sec,” in text-speak
• 'I'll return shortly,' in a text