For the subject, see Ovid, Metamorphoses, I, 568-723, where the story is told of how Jupiter transformed his beloved Io into a white heifer to protect her from the jealous Juno. Juno in response had the hundred-eyed Argus watch over Io, whom Mercury, sent by Jupiter, killed having lulled him to sleep by telling stories and playing on his flute. In the present work, Mercury is grasping his sword as Argus sits sleeping, and Io, the white heifer, looks on above.
Jordaens' first rendering of the subject, at Lyons, in which Mercury also reaches for his sword in a pose similar to that in the present lot, is of the early 1620s. The present lot is of similar size to two other depictions of the story, a Mercury lulling Argus to sleep (Anon. sale, Sotheby's, London, 16 July 1980, lot 226, ex-Anon. sale Christie's, London, 9 July 1976, lot 183) and a Mercury killing Argus (Anon. sale, Sotheby's, 16 July 1980, lot 100, see R.-A. d'Hulst in the catalogue of the exhibition, Jacob Jordaens, I, Antwerp, Koninklijk Museum voor Schone Kunsten, 1993, p. 110, under no. A26, notes 10 and 11). The composition of the latter picture is a variant of the Mercury killing Argus, which was exhibited in the 1992 Jacob Jordaens exhibition, no. A.77. That picture has been dated circa 1648-50, which is the likely date of execution of the present lot (it is also the date inscribed) and of the other two paintings illustrating different moments in the story; participation by the studio in the present work cannot be ruled out.