"He who walks in the dark will be punished. The Rabbis say it is a demon. Rabbi Yehuda bar Rabbi Yossi says it is a term for a robber. Rabbi Huna, in the name of Rabbi Yossi, says that bitter gall is made like layers of hair, with eyes in each layer, and with one eye he sees, and his eye is in his heart, and he does not rule over neither the shade nor the sun, but between the sun and the shade, and he rolls like a ball and rules from four hours until nine, and rules from the seventeenth of Tamuz until the ninth of Av, and anyone who sees him falls on his face.
Hezekiah saw him and fell on his face. Rabbi Pinchas bar Chama tells of an incident where someone saw him and fell on his face and was afflicted. Rabbi Shila bar Rabbi Yitzchak entrusted the books of law to the Teliya from the fourth hour to the ninth. Rabbi Yochanan entrusted the books of law so that they would not be lent out from the seventeenth of Tamuz until the ninth of Av. Beware of the demon Ishud Tzohorayim during midday."