The Gemara on our daf examines the background of one of the Canaanite kings who attacked the Children of Israel during the exodus from Egypt. The passage in Bamidbar 33:40 describes how the Canaanite king of Arad heard of the approach of the Children of Israel and waged a war against them, taking captives. The Gemara asks what it was that he heard that made him feel this was a moment in which Bnei Yisrael were vulnerable. Our daf goes on to explain that it was the sudden absence of the ananei ha-kavod (the clouds of glory that had accompanied them on their desert journeys up to that point) after Aharon ha-Kohen’s death (see Bamidbar 33:38-39) that gave him the sense that it was an opportune time to attack. (Tosafot point out that the discussion is not about the passage in Bamidbar 21:1, since that pasuk – verse – clearly indicates what the king heard.)
In an attempt to clarify the identity of the king of Arad, whose exploits seem to be similar to those attributed to other kings, the Gemara claims that he had a number of names. One suggestion is that his true name was Sihon; he was called Canaan because that was the name of his kingdom, and the nickname Arad stems from his sharing attributes with the arod – the wild donkey of the desert.
From a variety of sources it appears that the arod is one of two types of wild donkeys – equus hemionus, the Onager, or equus africanus, the African wild ass. The African donkey apparently existed in the land of Israel at that time. These animals are similar in their body structure and lifestyle to horses, and they live in dry areas and in the desert. With the domestication of almost all donkeys, few species now exist in the wild.