Hastings' Dictionary of the Bible (1898)
JU'NIPER. Unquestionably, the original intends the re-tem (Retama raetum), a shrub of the broom family, attaining a height of about 12 feet. This bush grows in the sandy regions of Arabia, northern Africa, and Spain, but is especially abundant in the desert Retem or Juniper Bush. ) of Sinai, and is often the only possible shelter. Under its shade travelers are glad to creep on a sultry day for a noontime nap, and thus Elijah lay and slept after his long journey. 1 Kgs 19:4-5. The retem has no main trunk, but consists of many stems, mostly small.
The roots are disproportionally massive and dense, and from them the Bedouins manufacture charcoal, which is sold in Cairo and other towns, where it brings the highest price, since, of all charcoal, it produces the most intense heat, Ps 120:4. In Job 30:4 we read of hunger so extreme that the bitter roots of this shrub are used for food. During the wanderings of the Israelites one of their stations was named Rithmah, doubtless from the abundance of the retem at that place. Num 33:18.