Psalms 134–136 share a significant number of words and phraseology, and though they appear in this sequence in the Psalter, we cannot automatically assume they were written at the same point in history. In light of the difficulty in establishing an absolute date for each composition, the present paper attempts to determine their dates in relation to each other. To accomplish this, it primarily relies on linguistic dating methodologies, comparing elements in the common words and phrases to identify signs of diachronic developments. In addition to linguistic evidence, other evidence—such as historical places mentioned within the composition—is adduced to affirm the proposed sequencing. The results show that the psalms are dated in the following order: 134, 136, 135, from the earliest to the latest. Both linguistic and internal evidence attest to this ordering. Though limited in its application, the diachronic analysis of duplicate material in psalms still presents itself as a useful tool for determining the relative dates of psalms. The importance of determining a psalm’s date—relative to the common material it may share with another biblical text—is important for those engaging in inner-biblical allusion and exegesis with respect to the Psalter.