Theophylact of Ohrid

Looking up to heaven, the Lord "sighed," on the one hand, prayerfully to the Father, that He might have mercy on the man, and as an example to us, that when we intend to do any good deed, we should look to God and ask His help for its accomplishment; and on the other hand, He sighs also out of compassion for human nature, how it has been so given over to the devil that it suffers such outrage and affliction from him.

Commentary on Mark ↗

Ambrose of Milan

Every sabbath we witness the "opening up" of a mystery. It is in outline form the type of that liturgical opening when the minister once touched your ears and nostrils. What does this mean? Remember in the Gospel, our Lord Jesus Christ, when the deaf and dumb man was presented to him, touched his ears and his mouth: the ears, because he was deaf; the mouth, because he was dumb. And he said: "Ephphatha," a Hebrew word, which in Latin means adaperire [be opened]. …

On the Mysteries 1.4 ↗

Bede

And looking up to heaven, he sighed; and said to him: Effeta, which is to say, Be opened. He looked up to heaven to teach that speech to the mute, hearing to the deaf, and healing to all infirmities, should be sought from there. He sighed, not because it was necessary for him to ask anything from the Father with a sigh, he who with the Father grants all things to those who ask, but to give us an example of sighing, when we invoke the aid of heavenly piety for our sins or those of our neighbors. …

On the Gospel of Mark ↗