Lift up my Hands and Sing In Front of Others?

Ps 57:9 I will give thanks to you, O Lord, among the peoples; I will
sing praises to you among the nations.

"Give thanks" in this verse literally means to "throw your hands up".

So David says he will throw his hands up among the people and sing to
his God among the nations. David felt that God was to be praise
outloud and expressively around others, anywhere in the world.

H3034

ידה

yâdâh

yaw-daw'

A primitive root; used only as denominative from H3027; literally to
use (that is, hold out) the hand; physically to throw (a stone, an
arrow) at or away; especially to revere or worship (with extended
hands); intensively to bemoan (by wringing the hands): - cast (out),
(make) confess (-ion), praise, shoot, (give) thank (-ful, -s,
-sgiving).