The Kitáb-i-Aqdas
29.these days of giving that precede the season of restraint   ¶16
Bahá’u’lláh enjoined upon His followers to devote these days to feasting, rejoicing and charity. In a letter written on Shoghi Effendi’s behalf1 it is explained that “the intercalary days are specially set aside for hospitality, the giving of gifts, etc.”
1 December 26, 1941 : Letters from the Guardian to Australia and New Zealand, p. 41