Mechanica Problemata is the most ancient text of mechanics in which one can find a germinal form of the Principle of Virtual Work used to predict the behavior of mechanical systems. Its impact on mechanical sciences cannot be underestimated, as it was influencing many scholars’ ideas at least until the formulation of the principle by d’Alembert and Lagrange. In present time the interest in Mechanica Problemata and its sources is mainly due to the need of understanding how the most fundamental principles of mechanics were invented. Indeed, we need guidance for inventing new mathematical models required for answering to the novel materials demand of contemporary technology. The present chapter is dedicated to the textual analysis of some parts of the Mechanica Problemata, based on what we believe to be the best available translation in the literature and on our careful inspection of the original Greek text. The presented exegesis shows that many scholars in the Renaissance and later centuries had some sources in common with the compiler of the Mechanica Problemata which lays the grounds for proving in the next chapter that it was inspired by a better quality source, most likely written in by Archytas of Tarentum and/or followers of his school.