Halakha Imamat 23:27: Mishneh Torah, Prayer and the Priestly Blessing, Shulchan Arukh, Orach Chayim & Sefer HaChinukh

The reader has (sometimes^*On the Day of Atonement.) to skip from passage to passage—both being on the same theme—as, for instance, that beginning, ".… After the death of the two sons of Aaron" (Leviticus chapter 16 verse 1) to that beginning, "And on the tenth day of this seventh month" (Numbers 29:7-11) which is in the weekly portion Emor. But he must take care not to recite by heart, it being forbidden to recite even a single word without referring to the text. Nor, when skipping, may he pause for a longer time than it takes the interpreter to translate the last verse [of the former passage].

To Not Skip In the Torah From One Subject to Another; And The Laws Of The Haftarah. Containing 4 S'ifim:
We skip in the Prophets, but we do not skip in the Torah from one section to another section. And this is in regards to two subjects where we are worried that perhaps the mind of the listeners will be confused, but with one subject, for example “Acharei Mot” [Lev. 16:1] and “Akh Be-asor” [Lev. 23:27] that the High Priest reads on Yom Kippur, we skip. And this is a long as one does not read by heart, as it is forbidden to recite even one word not from writing. And in the Prophets, we skip even with two subjects. And this is if one does not delay when skipping into [another] matter so that the congregation does not [have to] stand in silence [waiting]. And this is in regards to [reading] within one [book of the] Prophets, but from one [book of the Prophets] to another [book of the Prophets], we do not skip. And within the Trei Asar [i.e. Twelve Minor Prophets], we skip from prophet to prophet, as long as one does not skip from the end of the book to its beginning.

The commandment of the fast on the tenth day of Tishrei: To fast on the tenth day of Tishrei, and this is called The Day of Atonements (Yom HaKippurim), as it is stated (Leviticus 23:27), “But on the tenth of the month, etc. you shall afflict your souls.” The explanation appears in Sifra, Acharei Mot, Chapter 7:3): “[This refers to] affliction that causes a diminishing of the soul. What is this? This is eating and drinking.” And so [too,] did they, may their memory be blessed, explain in the Gemara (Yoma 74b). And the tradition also came about it, that it is forbidden for washing, anointing, wearing shoes, and sexual relations. And the language of Sifra, Parashat Acharei Mot, Chapter 8:3 is “From where [do we know] that Yom Kippur is forbidden for washing, anointing, [wearing shoes] and sexual relations? [Hence] we learn to say (Leviticus 23:32), ‘A Shabbat of shabbaton’” — meaning that the doubling of Shabbat (rest) indicates resting from these things [as well as] resting from nourishment of the body.