Genesis 2:2
1 The heavens and the earth were completed with everything that was in them. 2 By the seventh day God finished the work that he had been doing, and he ceased on the seventh day all the work that he had been doing. 3 God blessed the seventh day and made it holy because on it he ceased all the work that he had been doing in creation. 4 This is the account of the heavens and the earth when they were created—when the Lord God made the earth and heavens.
LXX Genesis 2:2
1 And the sky and the earth were finished, and all their arrangement. 2 And on the sixth day God finished his works that he had made, and he left off on the seventh day from all his works that he had made. 3 And God blessed the seventh day and hallowed it, because on it he left off from all his works that God had begun to make. 4 This is the book of the origin of heaven and earth, when it originated, on the day that God made the sky and the earth
Notes and References
"... The LXX agrees with the Samaritan Pentateuch (יששה) and S in reading “sixth” for “seventh” of MT. This reading probably derived from contextual theological harmonization because it was found difficult to explain how God could finish his work “on the seventh day” without having worked on that day. It is impossible to determine whether the easier reading of the LXX was based on an actual variant יששה or whether the exegetical tendency developed independently in all three sources."
Tov, Emanuel The Text-Critical use of the Septuagint in Biblical Research (p. 88) Eisenbrauns, 2015