gift, seriousness
摯 centers on a formal, weighty offering: a gift given with deep sincerity, or the grave seriousness that accompanies such an act.
摯 combines 執 (to hold, grasp) with 手 (hand), suggesting a hand holding something firmly. The meanings of gift and seriousness likely derive from the idea of formally presenting or grasping something with gravity.
A hand 手 firmly holding 執 a precious gift, presenting it with utmost seriousness.
For シ, imagine a solemn ceremony where a gift is presented: the hushed 'shh' sound cues シ, as everyone watches in serious silence.