鞍上人なく鞍下馬なし、鞍上人無く鞍下馬無し
あんじょうひとなくあんかうまなし
anjouhitonakuankaumanashi
JMdict entry #2141230
- expressions (phrases, clauses, etc.) idiomatic expression riding a horse so skillfully that it appears as if man and horse have become one