Persian source with Shoghi Effendi’s
authorized English translation. Paragraph 39 of 291.
Source (Persian)
چنانچهازانوار مشرقه از شمس محمّديّه مأثور است که برجميعانبياء در هرعهدی حکم صلاتنازلشده،نهايتآنکه در هر عصربهاقتضای وقت به قسمیوآدابی جديد مخصوص گشته.وچون در هرظهوربعد،آدابوعادات و علوم مرتفعه محکمه مشرقه واضحهثابته در ظهورقبلمنسوخ می شود لهذاتلويحاًبه اسم شمسوقمرذکر نمودهاند."لِيَبْلُوَکُماَيُّکُماَحسَنُعَمَلاً"
Shoghi Effendi Translation
The traditions established the fact thatinallDispensations the lawofprayerhath constituted a fundamental element of the Revelationof all the Prophets of God—a law the formand the manner of which hath been adaptedto the varying requirements of everyage. Inasmuch as everysubsequentRevelation hath abolished the manners, habits, andteachings that have been clearly, specifically, andfirmly established by the formerDispensation, these have accordingly been symbolicallyexpressedin terms of ‘sun’and‘moon’. “ThatHe might proveyou, which of you excel in deeds.”