The subject here is taken from an episode in the book of Genesis in which Jacob wrestled throughout the night with an unknown assailant (32:24-32). Luca Giordano depicts the moment at daybreak, the sun brightening the sky at left, when Jacob's opponent revealed himself to be an angel. Jacob's face is flushed with exhaustion, his hands and forearms still tensed in the tussle but his expression is one of astonished revelation as he now sees the angel, serene and unaffected by the night's exertion.
Giordano treated this subject on another occasion in a version now in a Naples private collection (O. Ferrari and G. Scavizzi, loc. cit., no. A052, illustrated), though the composition of the figures is reversed and the background landscape varied. At the time of the latter's exhibition in 2001, Denise Maria Pagano dated it to the end of the 1650s, citing the matured impact of Titian (loc. cit.). That dating was questioned later by Oreste Ferrari in 2003, however, who considered the warmer palette employed in both versions to be more indicative of Giordano's works of the mid-1660s (loc. cit.).