Let's take a look at the word shalal שָׁלָל. It means "spoils, booty, plunder" and according to Klein, derives from the root שלל meaning "to spoil, to plunder, to deprive" and has the following origin:
Akka. shalālu, OSArab. תלל (= to plunder), and Arab. thalla (= flock of sheep or goats). cp. the related base נשׁל.]The root נשל, in turn, means "to slip or drop off; to draw off."
Klein writes that this original root of שלל developed into two more meanings. One is found only once in the Bible:
שׁלל ᴵᴵ to draw out (sheaves).
— Qal - שָׁלַל he drew out sheaves (a hapax legomenon in the Bible, occurring Ruth 2:16 in the phrase שֹׁל־תָּשֹׁלוּ, ‘you shall draw out (from the bundles)’. [Arab. salla (= he pulled out, withdrew). A special sense development of שׁלל ᴵ. cp. the related base שׁלה ᴵᴵ.]
The root שלה - "to draw out" - gives us a number of familiar words:
- shilya שליה - "placenta" (drawn out of the womb)
- shilhey שלהי - "the latter part of, the end of" (literally going away, leaving)
- shaldag שלדג - "kingfisher". Klein presents this etymology: "Coined by H.N. Bialik (1873–1934) as the abbreviation of שׁוֹלֶה דָּגִים, ‘(the bird) that draws out fishes’, from שׁוֹלֶה, part. of שָׁלָה (= he drew out), and דָּג (= fish)." It is also the name of an elite unit in the Israeli army.
Prob. denominated from שַׁלְשֶׁלֶת (= chain). However, it is also possible that שׁלל in this sense is a Shaph‘el verb formed from לוּלָאָה (= loop), so that שׁלל ᴵⱽ would properly mean ‘to tie with loops’.
שָׂשׂ אָנֹכִי עַל־אִמְרָתֶךָ כְּמוֹצֵא שָׁלָל רָב׃
I rejoice over Your word as one who finds great spoil.
Shelal tzevaim - "a spoil of color(ed cloths)" took on the sense of "an abundance (or variety) of colors."
הֲלֹא יִמְצְאוּ יְחַלְּקוּ שָׁלָל רַחַם רַחֲמָתַיִם לְרֹאשׁ גֶּבֶר שְׁלַל צְבָעִים לְסִיסְרָא שְׁלַל צְבָעִים רִקְמָה צֶבַע רִקְמָתַיִם לְצַוְּארֵי שָׁלָל׃
“They must be dividing the spoil they have found: A damsel or two for each man, Spoil of dyed cloths for Sisera, Spoil of embroidered cloths, A couple of embroidered cloths Round every neck as spoil.”
So now we can see how one root developed into both very negative and very positive connotations.