Of whom (the most obvious antecedent being Melchizedek, but with regard to his typical significance, as referred to in Psalms 110:1-7) we have many things to say (the subject itself admits a lengthy exposition) and hard of interpretation, seeing ye are become (not, as in A.
V., "ye are") dull of hearing. Their dullness is the reason of the λόγος being δυσερμήνευτος. It was not that the subject was in itself inexplicable, or that the writer was incompetent to explain it; his difficulty was in adapting the interpretation to the capacity of his readers: "Non scribentis, sed vestro vitio" (Bengel).
It seems from γεγόνατε ("ye are become"), in this and the following verse, that the Hebrew Christians had even retrograded in spiritual perception. This is easily conceivable. As, through the teaching of St.
Paul especially, the tie between Christianity and Judaism became more and more broken, there was likely to be a certain reaction among the Hebrew Christians, who, having gone to a certain extent with the tide of thought, became conscious how far it was carrying them.
They would be inclined to cling the more fondly to their old associations from the fear of losing them altogether. Such retrogressions have been observable in other times of upheaval of old ideas.