farmer's hoeing fork
釽 centers on a specific farming tool: a hoeing fork used by farmers to break up or turn soil.
釽 combines 金 (metal) with 爪 (claw), suggesting a metal claw-like farming tool. The exact historical development is uncertain.
The left side 金 is metal, and the right side 爪 looks like a claw. Picture a metal claw-shaped fork that a farmer uses to hoe the soil.
For ヘキ, imagine a farmer using the hoeing fork to hack at the ground: hack -> ヘキ, and the metal claw breaks the earth.