# He has bent his bow toward us like an enemy, he has set his right hand like an adversary

A soldier has to bend his bow in order to shoot an arrow from it. Alternate translation: "He has prepared to kill us, like an enemy who has made his bow ready to shoot us" 

# he has set his right hand

He has pulled back the bowstring and is ready to shoot an arrow. Most bowmen pull back the string and arrow with their right hands.

# in the tent of the daughter of Zion

Calling Jerusalem  a "tent" emphasizes that it is the home of those who live there. Alternate translation: "who live in Jerusalem" 

# he has poured out his wrath like fire

"in his anger he has destroyed everything like a blazing fire"