In Aeschl. S. 212-3 the sun is called “bird of Zeus.” This unusual expression can be interpreted as an artistic kenning, a complicated metaphor which describes an object through a syntagm of type [X – YGEN.]. Two specific features are shared by both sun and eagle and, simultaneaously, distinguish them among birds and celestial beings, respectively. They are both considered ‘swift’ / ‘swift in flying’, cf. aietós ōkús en potanoĩs (Pind.), YAv. mərəγa … vaiiąm … āsišta and ōkéos ēelíoio (Mimn.), halíou pterúgi thoãi (Eur.), supakṣám āśúṃ patáyantam … sū́ryam (AV). They both ‘see things sharply’, cf. ēélios ... oksútaton ... eisoráasthai, aietós oksú láōn (Hom.), while the Sun-god has an ‘eagle eye’ in Vedic and Hittite texts, cf. páśyan gŕ̥dhrasya cákṣasā (RV), Hitt. ḫāranili šākuiškezzi.