What is the nature of the numeral ashtei-asar (meaning 11) as in וּבַיּוֹם הַשְּׁלִישִׁי פָּרִים עַשְׁתֵּי-עָשָׂר (Pinchas 29:20):
- What is the basic word? Is this using semichus, as in ashtaim of asar? If so, what does that mean? (I was thinking of some sort of contraction with shtayim, but that would be feminine.)
- Why does the the Torah sometimes use ashtei-asar and other times achad-asar as in וְהִנֵּה הַשֶּׁמֶשׁ וְהַיָּרֵחַ וְאַחַד עָשָׂר כּוֹכָבִים, מִשְׁתַּחֲוִים לִי (Vayeshev 37:9)?
- Does the basic word appear anywhere without the word asar?