rip up, tear down, raise, haul
撦 centers on forceful separation: ripping or tearing something apart, and by extension, raising or hauling something up with effort.
撦 combines 扌 (hand) with 奢, which likely contributes the sound and the idea of excess or largeness, suggesting a forceful hand action like tearing or hauling.
A hand 扌 beside 奢 (extravagance) suggests tearing something apart with excessive force, or hauling something heavy with a grand gesture.
For シャ, imagine a sharp tearing sound: 'shah!' as you rip the fabric. The hand 扌 makes the forceful 'shah' -> シャ action.