to put away, to cease, store up
戢 centers on stopping action and putting things away: ceasing activity, storing items, or setting something aside.
戢 combines 咠 (a component associated with gathering or whispering) and 戈 (a halberd or weapon). The idea of putting away weapons or ceasing conflict likely underlies the meanings of stopping and storing.
The left side 咠 looks like an ear 耳 over a mouth 口, as if listening and then falling silent. The right side 戈 is a weapon. Picture a weapon being put away after a command to cease: silence and storage together.
For シュウ, imagine putting away a shoe after a long day: shoe -> シュウ, and the weapon is stored just like the shoe.