一片一片削掉，木頭如此，數量也如此
同一個動作的兩層：手上真的在削木頭，以及把這個動作借去講任何慢慢變少的東西。
verb · B2
To cut small pieces off a piece of wood with a knife, slowly giving it the shape you want.
用小刀削木頭（成形）
核心畫面
Picture a small knife taking thin slices off a piece of wood. Each cut removes almost nothing. But the slices keep coming, the pile of grows, and after a while the wood is smaller and has a shape. That patient, one-slice-at-a-time removal is the whole idea.
可以想成一把小刀，一片一片削著一塊木頭。每一刀都只削掉薄薄一層，看起來幾乎沒差。但是刀一直下去，腳邊的木屑越堆越高。…更多收起
可以想成一把小刀，一片一片削著一塊木頭。每一刀都只削掉薄薄一層，看起來幾乎沒差。但是刀一直下去，腳邊的木屑越堆越高。過一陣子，木頭就變小了，也有了形狀。whittle 的重點就在這種「一次一點、慢慢來」的減法。From the word’s history
The word comes from Middle English whittel, which was a knife (and further back from Old English þwītan, 'to strike down, whittle'). So the knife in the picture is not a comparison — it is literally where the word came from.
來源字典說這個字來自中古英語 whittel，本來就是「刀」的意思，再往前是古英語 þwītan（砍、削）。所以畫面裡那把小刀不是比喻，它就是這個字的出身。
Wiktionary etymology supplied in this packet (kaikki:3f6f69a190036ae4:869888311) — Middle English whittel ('large knife') < thwitel < Old English þwītan.
One branch