In the context of the BiblIndex project, an online index of biblical quotations by the Church Fathers, the question of the boundaries to be drawn between quoted and citing texts is of significant importance. The distinction between the Bible and patristic texts is not sufficiently nuanced to account for the phenomena of intrabiblical intertextuality, the fluctuations in the canon at the time when the first Christian writings were produced, or the influence of patristic quotations on the canonical form that biblical texts will subsequently take. This paper addresses the first of these problems by examining the reuse of psalmic texts in the New Testament. The numerical analysis method employed is founded on a comparison of Biblical verses, utilising similarity measures based on various natural language processing operations, namely tokenisation, lemmatisation, part-of-speech tagging, stop-word filtering and synset assignment. The textometric measures provide a framework for the numerical assessment of syntactic, lexical, and semantic similarities between textual units. The aim is to employ these measures to detect instances of textual reuse in a comprehensive manner and subsequently establish a typology that can be applied to other biblical and patristic corpora.