John 8:36

ἐὰν οὖν ὁ υἱός. As before, any son is meant. ‘If the son emancipates you, your freedom is secured; for he is always on the spot to see that the emancipation is carried out.’ The statement is general, but with special reference to the Son of God, who frees men by granting them a share in His Sonship. If they will abide in His word (John 8:31), He will abide in them (John 6:56), and will take care that the bondage from which He has freed them is not thrust upon them again.

ὄντως. Here only in S. John: comp. Luke 23:47; Luke 24:34; 1 Timothy 5:3; 1 Timothy 5:5; 1 Timothy 5:16. It expresses reality as opposed to appearance; ἀληθῶς (John 8:31; John 4:42; John 6:14; John 7:40) implies that this reality is known.