kadācid atha govindo
rāmaś cādbhuta-vikramaḥ
vijahratur vane rātryāḿ
madhya-gau vraja-yoṣitām
kadacit -- on one occasion; atha -- then; govindah -- Lord Krishna; ramah -- Lord Balarama; ca -- and; adbhuta -- wonderful; vikramah -- whose deeds; vijahratuh -- the two of Them played; vane -- in the forest; ratryam -- at night; madhya-gau -- in the midst; vraja-yoshitam -- of the women of the cowherd community.
This verse introduces a new pastime. According to the acaryas, the occasion mentioned here is the Holika-purnima, a day also known as Gaura-purnima.