石頭いしあたま (ishiatama)

彼かれは 石頭いしあたまだから 言いっても 無駄むだです

It is a waste of time telling him as he is stubborn.

あいつは石頭だ. He is pigheaded.あいつは石頭だ. 〈頑固だ〉 He is as obstinate as a mule.あいつは石頭だ. 〈鈍い〉 He is a real blockhead.あいつは石頭だ. He is really thickheaded.あいつは石頭だ. 〈ぶつかって〉 His skull is as hard as granite.石頭希遷、及び、石頭門下の天皇道悟、丹霞天然、雲巌曇晟、投子大同など。

It includes Kisen SEKITO as well as his disciples such as Dogo TENNO, Tennen TANKA, Donjo UNGAN and Daido TOSU.