This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 揔 is uncertain. It visually contains 扌 (hand) and 怱, but the component relationship is unclear.
With no clear meaning, focus on the shape: a hand 扌 beside 怱, which looks like a hurried heart. Imagine a hand trying to calm a flustered heart, but the result is uncertain.
For ソウ, imagine the hand 扌 trying to sew (ソウ) the pieces of the right side 怱 together, though the meaning remains unclear.