72. The labour of the canal, the passage of the Tigris, and the victory, are described by Ammianus (xxiv. 5, 6), Libanius (Orat. Parent. c 124-128 p. 347-353), Greg. Nazianzen (Orat. iv. p. 115), Zosimus (1. iii. [c. 24, p. 159 sqq.] p. 181-183), and Sextus Rufus (de Provinciis, c. 28).