it is a silly goose that comes to a fox's sermon

/ɪt ɪz ɐ sˈɪli ɡˈuːs ðat kˈʌmz tʊ ɐ fˈɒksɪz sˈɜːmən/

/ɪt ɪz ɐ sˈɪli ɡˈuːs ðæt kˈʌmz tʊ ɐ fˈɑːksɪz sˈɜːmən/

used to advise individuals to be cautious and discerning in choosing whom they trust and follow for advice or guidance