From The Gospel of Mark by Mary Healy, comnenting on Mark 7:33-35:
Many of Jesus’ healings take place in full public view (see 3:3), but here, in contrast, he takes the man off by himself (see also 8:23). This detail suggests that Jesus intuitively understands the unique needs of each person. For some people it is important to have a private encounter, away from the stares of the crowd, so that Jesus can minister to their needs one-on-one. Jesus performs the healing in no less than seven steps, as if speaking in sign language so the deaf man can follow what he is doing. After taking him aside, he puts his finger into the man’s ears, spits, touches his tongue, looks up to heaven, groans, and says to him, Ephphatha! The spitting should be interpreted as Jesus’ spitting on his own finger, then touching it to the man’s tongue, so that both his impaired organs are healed by Jesus’ direct touch. In the ancient world saliva was considered to have therapeutic qualities. Jesus’ looking up to heaven is a gesture of prayer (see 6:41), expressing his total reliance on the Father. It is the only place in the Gospel where Jesus is said to groan (or “sigh,” RSV, NRSV, JB, NJB), perhaps because of his grief over a person so ravaged by the effects of the fall. St. Paul uses a form of the same word to speak of the “inexpressible groanings” of the Spirit as he intercedes for us (Rom 8:26).