And looking up to heaven, He sighed deeply: Since Jesus was looking up to heaven when he sighed, his sigh is probably best understood as a prayerful gesture.
Ephphatha is an Aramaic word that Mark translates for his audience (see also 3:17; 5:41; 14:36; 15:34). These are not magical words. Mark is simply sharing some of the original words Jesus spoke.
Matthew and Luke do not seem to have attributed any special importance to the Aramaic words of Jesus, since they did not include them in their Gospels.