What does it mean and where did it come from?
First though: How did we find ourselves in a "love relationship" with God? It is done through the perfect attribute of the character of God. That attribute is God's love. "Love" in the Greek is agape. It is derived from the Hebrew root a-gaab, which means "TO SHARE A BREATH."
Think about that word as you remember God breathing life into Adam, and Ezekiel and the dry bones. Think about it as our Lord Jesus Christ saying to the disciples after His resurrection, "receive the Holy Spirit," and He breathed on them.
The basic word for "breath" and "spirit" are the same in both Hebrew and Greek. AGAPE, the word we use for God's unconditional love, literally means "oneness of spirit or shared breath".
This love is the element of character which is able to identify with others. God alone holds this attribute in perfection. God is love.
And it is by His love that He redeemed us through His Son, our Lord Jesus Christ.
So yes, when God chose to love us and we received that love by accepting our Lord Jesus Christ as Savior we literally shared God's breath. We took His breath away.