
Resting may date from between January and March 1898. This date is based on the sole record of the painting, when it was exhibited by Whistler in A Collection of Selected Works by Painters of the English, French & Dutch Schools, Goupil Gallery, London, 1898 (cat. no. 23).
It is possible that this may be the same as The Little White Sofa y258, which was originally dated to the mid-1880s, but is now considered, mainly on the basis of the signature, to date from 1898, and was bought by Alexander Arnold Hannay (1858-1927) in 1898 or 1899.

Resting, Whereabouts unknown

The Little White Sofa, Fogg Art Museum
One title is known:
Unknown. Table Talk described it as 'nothing but a shapeless, meaningless mass of colour-blotches.' 3

The Little White Sofa, Fogg Art Museum
However, it may be The Little White Sofa y258, which is a slightly unusual composition, showing a draped nude lying on a white-draped sofa.
Unknown.
Unknown.
Unknown.
Unknown.
Unknown.
Several critics quoted in the Goupil catalogue commented that it was small, but none help to identify it. Table Talk thought 'Mr. Whistler has overstepped the limits: it is nothing but a shapeless, meaningless mass of colour-blotches.' 4

The Little White Sofa, Fogg Art Museum
It is possible that this could apply to a somewhat confusing little oil, The Little White Sofa y258, reproduced above.
1: A Collection of Selected Works by Painters of the English, French & Dutch Schools, Goupil Gallery, London, 1898 (cat. no. 23).
2: YMSM 1980 [more] (cat. no. 497).
3: Table Talk, 19 March 1898, quoted in exh. cat., Goupil 1898 (2nd edition) p. xv (cat. no. 23).
4: Table Talk, 19 March 1898, quoted in exh. cat., Goupil 1898 (2nd edition) p. xv.