This brief article investigates the authenticity of a letter attributed to Sakya Paṇḍita (sa skya paN+Dita). The letter, titled Bu slob rnams la spring ba, has been cited by several scholars as source material on early Mongol-Tibetan relations. However, Jackson points to several factors that bring the letters authenticity into doubt, including the absence of any reference to the letter until the 16th century. Further, there are several stylistic elements of the letter which are unique among Sakya's writings. (Ben Deitle 2006-02-02)