to manipulate, pricker for a lamp wick
掭 centers on using a tool to adjust or manipulate something small, like a lamp wick. The idea of a pricker extends naturally to any careful manipulation with a pointed instrument.
掭 combines 扌 (hand) with 忝, which likely contributes the sound and relates to the idea of adding or inserting. The exact historical development is uncertain.
The hand radical 扌 beside 忝 suggests a hand using a thin tool. Picture a hand holding a pricker to adjust a lamp wick, carefully manipulating the flame.
For テン, imagine using a pricker to adjust a lamp wick inside a tent: tent -> テン, and the hand carefully manipulates the wick.
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