I'm not familiar with the statement, but if it means 'watch' as in 'be careful' it might translate as bi faicilleach leann agam (something like "bee fie [as in fee fie fo fum!] kill yokh lee own [as in Ow! + n] akm": bee fiekillyokh leeown akm); 'watch' as in 'see' would be coimhead leann agam ("coy [as in coy meaning shy] yat": coyyat leeown akm); and 'watch' as in 'guard' would be cùm faire leann agam ("coom faaruh leeown akm").

Of course, others might know different...