6 (He did not know what to say, they were so frightened.)

6 For he did not know what to say, for they were terrified.

6 For he wist not what to say; for they were sore afraid.

6 He said this because he didn’t really know what else to say, for they were all terrified.

6 because he did not know what to say, for they were greatly afraid.

6 Peter did not know what to say, because he and the others were so frightened.

6 For he knew not what to answer; for they became sore afraid.

6 For he knew not what he should say, for they were filled with fear.

6 (Peter didn’t know how to respond. He and the others were terrified.) 

6 because he did not know what he should say, since they were terrified.

6 He did not know what to say, for they were terrified.

6 (For he did not know what he should answer, because they were terrified.)

6 Peter didn’t really know what to say, because they were so afraid.