pick, pinch, summarize
抓 centers on using the fingers to grasp or compress something small: picking, pinching, or squeezing. The summarize sense extends this idea to extracting the essential points.
抓 combines 扌 (hand) with 爪 (claw/nail), suggesting a hand action involving the fingers or nails, such as pinching or picking. The exact historical development is uncertain, but the component relationship is visually clear.
A hand 扌 using its claws 爪 to pick up a tiny object or pinch something tightly.
For ソウ, imagine pinching a single grain of salt (ソルト) between your fingers: salt -> ソウ, and the pinch extracts just that one grain.
to pinch; to nip