{Upon the sun} (epi ton h(886c)ion). Not eis (into) as in
verses  2,3,4 . The fourth trumpet ( 8:12 ) affected a third of
the sun, moon, and stars with a plague of darkness, but here it
is a plague of extreme heat. {To scorch with fire} (kaumatisai
en puri). First aorist active infinitive of kaumatiz(935c), late
(Plutarch, Epictetus) causative verb (from kauma, heat), in
N.T. only here and verse  9  Mt 13:6  Mr 4:6 . The addition of
en puri (in fire, with fire) intensifies the picture.