Ibn Ezra on Leviticus 23:10

וטעם להזכיר כי תבאו אל הארץ. בעבור שישמרו כל השבתות במדבר ופסח בהר סיני כי זו הפרשה סמוכה להקמת המשכן: Scripture reads, When ye are come into the land (v. 9),⁶¹After stating the laws of the Sabbath and Passover. so that Israel would observe all the Sabbaths in the wilderness and the Passover⁶²Israel offered only one Passover sacrifice in the wilderness. They did this when they camped around Mount Sinai. See I.E. on Ex. 29:42 (Vol. 2, pp. 620,621). This celebration took place close to the time of the erection of the tabernacle, for the mishkan was erected on the first day of Nisan. Israel celebrated the Passover soon after. at Mount Sinai.⁶³And in the merit of observing the Sabbath and Passover enter the Land of Israel, for after leaving the wilderness of Sinai, Israel was supposed to enter the Promised Land (Weiser). This section was given close to the [time of the] erection of the tabernacle.⁶⁴The revelation of the laws in the Book of Leviticus commenced with the completion of the tabernacle. See Ex. 40:34-38; Lev. 1:1.

וטעם דבר אל בני ישראל. שיתחברו ואחר כן ואמרת אליהם: [SPEAK UNTO THE CHILDREN OF ISRAEL.] This means speak unto the children of Israel and tell them to gather. Afterwards,⁶⁵After they gather. say unto them…⁶⁶What follows.