sounding sticks
柝 centers on wooden sticks struck together to produce a sharp sound, used for signaling or keeping rhythm.
柝 combines 木 (tree/wood) with 斥, which likely contributes the sound. The character represents wooden sounding sticks.
The left side 木 is wood, and the right side 斥 looks like an axe splitting wood. Imagine splitting a log into two sticks that you clap together to make a sharp sound.
For タク, picture clapping two wooden sticks with a sharp 'tack' sound: tack -> タク, and the sound echoes through the night.