Leviticus 25:1–55 begins by mentioning a specific location. This type of introduction is incredibly rare in the book of Leviticus (see also Leviticus 26:46). The description of Mount Sinai is designed to underscore the authority of the following command. That is, Moses received these instructions directly from the mouth of God while on top of Mount Sinai.
1 The LORD spoke to Moses on Mount Sinai, saying,