It is
sometimes said that Mary’s surprise was because it was not customary for a man
to give a greeting (ἀσπασμός, 1:41, 44; 11:43; 20:46) to a Jewish woman. But
the rabbinic evidence is late and scanty (SB II, 99), and Mary’s wonder was
occasioned more by the character of a greeting which addressed her in such
exalted terms, and implied that, like the great men of OT times, she was chosen
to serve God and to be empowered by him (W. C. van Unnik, ‘Dominus Vobiscum:
The Background of a Liturgical Formula’, in A. J. B. Higgins (ed.), New
Testament Essays, Manchester, 1959, 270–305). (I. Howard Marshall, The
Gospel of Luke: A Commentary on the Greek Text [New International Greek
Testament Commentary; Exeter: Paternoster Press, 1978], 66.)