Book of Jubilees 50:13
The man who does any of these things on the Sabbath shall die, so that the children of Israel shall observe the Sabbaths according to the commandments regarding the Sabbaths of the land, as it is written in the tablets, which He gave into my hands that I should write out for thee the laws of the seasons, and the seasons according to the division of their days. Herewith is completed the account of the division of the days.
Background and history of Book of Jubilees, and issues with this book.
R. H. Charles, The Book of Jubilees, in The Apocrypha and Pseudepigrapha of the Old Testament, vol. 2 (Oxford: Clarendon Press, 1913). Public domain in the United States (published 1913). Charles died in 1931, so the book is in the public domain in the United Kingdom. The verse text is the Joshua Williams transcription at pseudepigrapha.com. Jubilees 1:8 and 1:9 are divided at the break in the 1902 Clarendon scan (archive.org bookofjubileesor00char), where verse 9 begins “For they will forget.” That scan also numbers the angel-of-the-presence sentence as 1:29. Editorial brackets in the translation are Charles’s.