Chasidut for Berakhot 62:7

And truly why should dear friends be haughty towards one another? Why not recognize yourselves and your friends as pure angels - the hosts of God - whom He has sent to this world, to conquer it for His sake? See that the God of the heavens and earth is called the Lord of hosts - meaning the Lord of armies. And what armies does the Holy One, blessed be He, have in this world? Channah hinted to this in her prayer (that used this name of God). And the Sages, may their memory be blessed, said (Berakhot 31b) that with this name, she intended to say, "Master of the world, from all of the many armies You have created in Your world, is it difficult in Your eyes to give me one child?" We can already see everything from this.