Berean Study Bible
We have much to say about this, but it is hard to explain, because you are dull of hearing.

King James Bible
Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing.

American Standard Version
Of whom we have many things to say, and hard of interpretation, seeing ye are become dull of hearing.

Darby Bible Translation
Concerning whom we have much to say, and hard to be interpreted in speaking [of it], since ye are become dull in hearing.

Douay-Rheims Bible
Of whom we have much to say, and hard to be intelligibly uttered: because you are become weak to hear.

English Revised Version
Of whom we have many things to say, and hard of interpretation, seeing ye are become dull of hearing.

Young's Literal Translation
concerning whom we have much discourse and of hard explanation to say, since ye have become dull of hearing,