首楞嚴義疏注經 2.301

2.301

於是大眾非無學者聞佛此言，茫然不知是義終始，一時惶悚，失其所守。

Thereupon, those in the great assembly who were not non-learners, hearing these words of the Buddha, were bewildered and did not know the beginning or end of this meaning; all at once they were terrified and lost their bearings.