Emphysao means to breathe on or breathe into — appearing once in the NT at one of the most theologically pregnant moments: John 20:22, when the risen Jesus 'breathed on' the disciples and said 'Receive the Holy Spirit.' The word deliberately echoes Genesis 2:7 where God 'breathed into' Adam's nostrils the breath of life.
John 20:22 is the Johannine Pentecost — Jesus bestowing the Spirit on the disciples on resurrection evening. The deliberate use of emphysao (the same verb used in the Septuagint for Genesis 2:7's creation of Adam) signals that what is happening is a new creation. Just as God breathed life into the first Adam, the last Adam (1 Corinthians 15:45) breathes the Spirit into the new humanity. This is the fulfillment of Ezekiel 37:9, where God commands the four winds to breathe life into the dry bones of Israel. The single NT occurrence carries the weight of the entire biblical theology of divine breath (ruach/pneuma): life, creation, resurrection, and the Spirit are all one reality.