Is it "Vay-SHA-vucha" or "Va-YASH-vucha" in Anim Zemiros? I've heard both, and seen both in different siddurim. Any insight?
Vayshavucha is a simple verb, vayashvucha is causative. So, from what I can tell, vayshavucha would mean the neviim directly "summed up" Hashem by describing his works. Vayshavucha would mean the neviim described Hashem's works, and that caused Hashem to be "summed up".
In short, I don't see why someone should have an hakpada for one over the other.