ܒܝܣܦܢܐ byspnʾ messenger, courier
Parth. bayaspān; MP bayaspān [byʾspʾn'] messenger, envoy (CPD 17); SW form MP dayaspān > dēspān; both forms come from OIr. *dwai-aspāna- ● am 2, 628, 10 ◆ LS 81b
Parth. bayaspān is the technical term to indicate the horse-courier which carries out the royal postal service. It is not certain whether the second /a/ of bayaspān is long or short: in Pahlavi orthography, a short /a/ is represented by aleph only if in initial position, or at the beginning of the second element of a compound, as in our case; consequently, MacKenzie reads bayaspān, with a short second /a/; same reading in Bailey 1943, 46, who adds that the medial aleph appears at the beginning of the second component of a compound, as in MP arvandasp [ʾlwndʾsp]. On the contrary, Sundermann (1998, 122 n. 6 and 128 f.), basing himself on the Parthian inscriptional spelling [byʾspn] (see Humbach – Skjærvø 1978–1983, 3/1, 90) and on ManMP byʾspʾn, suggests the possible reading bayāspān, with a long second /a/, as in the many names ending in -āsp (same reading in Nyberg 46 and Carlsen 1984, 116 f.). However, the question remains uncertain: in fact, the strongest evidence in favour of the long /a/ is the ManMP spelling, but—according to Boyce 1975, 15—in ManMP orthography, as in Pahlavi script, a short /a/ beginning the second element of a compound is represented by an aleph. See also Durkin-Meisterernst 2004, 120, s.v. ManMP and ManParth. byʾspʾn, who leaves the question unsolved, transcribing /bayaspān/, /bayāspān/, followed by a question mark.