A search for “«ep»” or “«e[p]»” in the search window of Mattis List’s Shījīng Rhyme Browser (http://digling.org/shijing/wangli/), where Shi Jing rhymes are presented in the Baxter-Sagart (2014) reconstruction, returns three words in rhyming position: 攝瘞介. None of them is part of an identifiable rhyme sequence: consequently, no *-ep rhyme sequences can be found in the Shi Jing under the Baxter-Sagart 2014 system. This does not necessarily reflect reality. If such rhyme sequences existed, they would presumably be hidden under the label *-[a]p: words tentatively reconstructed with *-a- between brackets because they are indistinguishable from *-ap in Middle Chinese, but have unexplained connections (xiesheng, word-family) to words with vowel *-ep. We are therefore looking for a set of *-[a]p words in the B&S 2014 system which are (a) connectable to one another by rhyme, (b) self-contained, i.e. without rhyme connections to other *-[a]p or *-ap words, and (c) have a pattern of contacts to *-ep words.
A cluster of six words fit the description: 捷 *[dz][a]p > dzjep > jié ‘victory’, 業 *[m-qʰ](r)[a]p > ngjaep > yè ‘work (n.)’, 葉 *l[a]p > yep > yè ‘leaf’, 韘 *l̥[a]p > syep > shè ‘archer’s thimble’, 甲 *[k]ˤr[a]p > kaep > jiǎ ‘1st heavenly stem; fingernail’, 涉 *[d][a]p > dzyep > shè (this last word is not part of Baxter and Sagart 2014 but could have been reconstructed with [a]). The interrhyming pattern between them is illustrated by the chart below, where for instance ‘捷—260,167—業’ is to be understood as ‘捷 and 業 rhyme together in odes 260 and 167’ (the numbers are the standard ode numbers—stanza numbers are omitted):
捷—260,167—業—304—葉—60—韘—60—甲
捷—260,167—業—304—葉—34—涉
This cluster is self-contained: there are no rhymes with other *-[a]p words, or with *-ap words, in the Shi Jing.
I now present the evidence—duly noted by Bill in our database— for contacts to *-ep in some of these words:
1. 捷 *[dz][a]p > dzjep > jié ‘victory’. Words with phonetic 疌 have MC -ep in division 4: 蜨 dep; MC -eap in division 2: 萐 sreap, dzreap; 疀 tsrheap. and MC -jep in division 3. There are no division-1 words. This can only indicate OC *-ep. The sole exception to this pattern is 𧚨, MC tship, indicating OC *-ip.
2. 葉 *l[a]p > yep > yè ‘leaf’. All eight type-A words in this series (GSR 633) have division-4: MC -ep, indicating OC *-ep. If the OC vowel were *a, one would expect MC -ap in type A. There is one problem: the word 世 *l̥ap-s > syejH > shì ‘generation’, whose *a vowel seems clearly identified by the rhyming sequence 揭害撥世 in 255.8, is probably part of the same word-family as 葉, which we want to reconstruct with *-ep. This is probably the result of *-ep-s changing to *-et-s (*-p-s > *-t-s is a regular and very early western Zhou change), and then *-et-s shifting to *-at-s—a commonly development in western odes; 255 is a western ode. Further on this, see (link in construction).
3. 甲 *[k]ˤr[a]p > kaep > jiǎ ‘1st heavenly stem; fingernail’. This word has a probable word-family connection to 介 *kˤr[e]p-s > keajH > jiè ‘armour; scale of animals’, 疥 *C.kˤr[e][p]-s > keajH > jiè ‘scabby disease’. Normally we should expect an OC *kˤrep to evolve to MC kaep, but MC sources do not keep a strict distinction between -aep and -eap.
In conclusion we should emend the reconstruction of 捷, 業, 葉, 韘, 甲 and 涉 *from *-[a]p to *-ep, and recognize rhyming sequences in *-ep in odes 34, 60, 167, 260, 304. This could not be not done in Baxter and Sagart (2014) because we lacked the knowledge that the six words under discussion form a rhyming ring in the Odes.
Post Scriptum (same day):
葉 *lep ‘leaf’ and 甲介 ‘scale, fingernail’, both based on a root *kˤrep, have western Sino-Tibetan cognates. For ‘leaf’, cf. the sets under PST *lap ‘leaf’ in Coblin’s handlist p. 102 and in the STEDT dabase: #824 PTB *s-lap LEAF / LEAFLIKE PART. Written Tibetan ‘dab-ma ‘leaf’ is from *’lab. The doublet lo-ma ‘leaf’ is perhaps from law-ma > lab-ma. For ‘scale’, Tibetan khrab ‘shield, coat of mail, fish scales’, Achang ŋa⁵⁵ kjap⁵⁵ ‘fish scales’.
These are two more examples of the vowel correspondence OC *-e- : western ST *-a-.