Stories We Like: A Guide to the Comma
Old English bolster "bolster, cushion, something stuffed so that it swells up," especially "long, stuffed pillow," from Proto-Germanic *bolkhstraz (cf. Old Norse bolstr, Danish, Swedish, Dutch bolster, German polster), from PIE *bhelgh- "to swell" (see belly (n.)).
mid-15c. (implied in bolstered), "propped up, made to bulge" (originally of a woman's breasts), from bolster (n.). Figurative sense is from c.1500, on the notion of "to support with a bolster, prop up." Related: Bolstering.
The Hebrew word _kebir_, rendered "pillow" in 1 Sam. 19:13, 16, but in Revised Version marg. "quilt" or "network," probably means some counterpane or veil intended to protect the head of the sleeper. A different Hebrew word (meraashoth') is used for "bolster" (1 Sam. 26:7, 11, 16). It is rightly rendered in Revised Version "at his head." In Gen. 28:11, 18 the Authorized Version renders it "for his pillows," and the Revised Version "under his head." In Ezek. 13:18, 20 another Hebrew word (kesathoth) is used, properly denoting "cushions" or "pillows," as so rendered both in the Authorized and the Revised Version.