On the words “Speak to the entire congregation of Israel,” Rashi writes: “This teaches us that this parshah was spoken at Hakhel [a great gathering of the entire Jewish people], because most of the corpus of the Torah depends on it.” Rashi’s commentary is based on the Midrash Rabbah, which also compares the content of our parshah with the Ten Commandments. Various other commentaries (like the Ibn Ezra, Nachmanides, and the Chizkunei) bring out the full connection between the commandments in our parshah and the Ten Commandments, though each has his own variation (apparently based on the reading of the Midrash Rabbah that they had before them).
Actually, the Ten Commandments appear twice. The first time is when the Torah narrates the receiving of the Ten Commandments at Mt. Sinai in parshs Yisro. The second time is in parshas Va’eschanan, when Moses retells the story of the giving of the Ten Commandments. Since the sages tell us that our parshah also contains direct parallels to the Ten Commandments, the difference being that the commandments as they are worded in the Ten Commandments (both in parshas Yisro and parshas Va’eschanan) are considered general rules that allude to all 613 commandments, while in our parshah they are worded in a more particular manner. (see inner.org for development of this issue)
It's not very difficult to find the Ten Commandments 'hiding' in Parshas Kedoshim, at least most of them. (see Tanach.org for elaboration of the patterns and deeper meaning in the Parsha)
I. ANOCHI19,2 ANI HASHEM ELOKEICHEMmitzvos bein adam la-MakomII. LO SIHIYEH19,4 ANI HASHEM ELOKEICHEMmitzvos bein adam la-MakomIII. LO SISA - [no apparent parallel] properly publicize the Name of G-d19,5-10 (Pigul & Peah)Thinking selfishly about oneself, causes G-d’s Name to be desecrated Es kodesh HASHEM chillelIV. SHABBOS19,3 ANI HASHEM ELOKEICHEMmitzvos bein adam la-MakomV. KIBBUD AV19,3 ANI HASHEM ELOKEICHEMmitzvos bein adam la-MakomVI. LO TIRTZACH19,15- 'lo ta'amod al dam re'echa' ANI HASHEMMitzvos bein adam le–chaveiroVII. LO SIN'AF19,20-22 - the laws of 'shifcha charufa' ANI HASHEMMitzvos bein adam le–chaveiroVIII. LO SIGNOV19,11 - 'lo signovu...'ANI HASHEM Mitzvos bein adam le-chaveiroIX. LO SA'ANEH19,12 be-re'acha ED SHAKER - 'lo tishav'u bi-shmi la-SHAKER...'ANI HASHEM Mitzvos bein adam le-chaveiroX. LO SACHMOD19,18- 'lo sa'ashok et re'acha ...' ANI HASHEMMitzvos bein adam le-chaveiro