The Hebrew text On the Heavens and the World, ascribed to Ibn Sīnā, is an interesting and intriguing composition. It dates from the 13th century and was quite influential. It is not a translation of any text of Ibn Sīnā known to us, but is related to the (pseudo-Avicennian) Latin De celo et mundo, which appears in the 1508 Venice edition of translations of Ibn Sīnā. The Latin and Hebrew texts differ widely and the relation between them is far from being clear. Both are in sixteen chapters, the titles of the chapters are the same, but the texts are only roughly similar. The Hebrew text often offers short, incomplete summaries of the Latin arguments. On the other hand it includes many passages which have no parallel in the Latin. There are two possible explanations of the perplexing relationship between the two texts: either that there was more than one version of the Latin (or of the original Arabic) text, or that the translator, Shlomo ben Moshe of Laguiri wrote a kind of paraphrase. The paper shows that the second explanation is correct and offers a preliminary study of the sources and the aims of the Hebrew text.