Ram (yang) is homophonous with yang (the long lines of the trigrams), and three rams (sanyang) is homophonous with the trigram with three long strokes, which stands for 'spring'.
For a jade carving depicting this theme see R. Keverne, ed., Jade, London, 1991, p. 162, fig. 88 and another included in the O.C.S. exhibition, Jade throughout the ages, Victoria and Albert Museum, London, 1 May - 22 June, 1975, Catalogue, no. 401. Two smaller white jade examples are included in the exhibition, Exquisite Jade Carvings: Figures, Animals, Ornaments, The University of Hong Kong, 6 December 1996 - 7 February 1996, Catalogue, pp. 148-149, nos. 124-125. Compare, also, a large group of three rams published by S. Nott, Chinese Jade Throughout the Ages, New York, 1937, pl. LXXII and another large example illustrated by R. Kleiner, Chinese Jades from the Collection of Alan and Simone Hartman, Hong Kong, 1996, p. 245, no. 194. Also included by R. Kleiner, op. cit., p. 237, no. 186 is a three-ram group of similar size to the present lot.