Histories
Herodotus
Herodotus. Godley, Alfred Denis, translator. Cambridge, MA; London: Harvard University Press; William Heinemann, Ltd., 1920-1925 (printing).
To bury people alive is a Persian custom; I have learned by inquiry that when Xerxes' wife Amestris reached old age, she buried twice seven sons of notable Persians as an offering on her own behalf to the fabled god beneath the earth.