PL 49, col. 532

Collationes (Joannes Cassianus), J. P. Migne

In English: The Conferences of John Cassian 2.6

ultra illam eremum Thebaidos ubi quondam fuerat
beatus Antonius commoratus, minus cauta discretione
permoti, euntes per extentam solitudinis
vastitatem, nullam escam penitus sumere decreverunt,

Text from the Corpus Corporum (University of Zurich).