Wahe is a statement of awe and ecstasy.
Guru is the one who brings us from darkness to light.
Wahe Guru is an expression of complete ecstatic awe of the Divine.
This is a mantra of the Infinity of ecstasy and dwelling in God. It expresses the indescribable experience of going from darkness to light (from ignorance to true understanding). It is the Infinite teachers of the soul. A trikutee mantra, it balances the energies of the generating, organizing, and transforming principles. It expresses ecstasy through knowledge and experience. It is the gurmantra, which triggers the destiny. It is said that chanting Wahe Guru is equivalent to chanting Har 11,000 times.
This mantra information is from Spirit Voyage