1.
leave it to the specialist; each job is best done by a professional
A proverb meaning that rice cakes are best made by a rice-cake maker: any task is done best by someone who specializes in it, so an amateur should not attempt it. Often said when deciding to call in a professional.
やはり餅は餅屋だね。
It really is best to leave it to the experts.
Used in everyday conversation, often with やはり or やっぱり after an amateur attempt has failed, or as a reason for hiring a professional.