The name of the Parshah, “Bechukotai,” means “in My statutes” and it is found in Leviticus 26:3.
G‑d promises that if the people of Israel will keep His commandments, they will enjoy material prosperity and dwell securely in their homeland. But He also delivers a harsh “rebuke,” warning of the exile, persecution and other evils that will befall them if they abandon their covenant with Him.
Nevertheless, “Even when they are in the land of their enemies, I will not cast them away; nor will I ever abhor them, to destroy them and to break My covenant with them; for I am the L‑rd their G‑d.”
The Parshah concludes with the rules on how to calculate the values of different types of pledges made to G‑d, and the mitzvah of tithing produce and livestock.
Learn: Bechukotai in Depth
Browse: Bechukotai Parshah Columnists
Prep: Devar Torah Q&A for Bechukotai
Read: Haftarah in a Nutshell
Play: Bechukotai Parshah Quiz

Considering what is taught by Bechukotai Parshah how can one explain the Holocaust? We were exiled from Israel for hundreds of years and only allowed to return after the Holocaust.
I really do not understand. Could some please explain it to me?
From the article, 'The Rebbe on the Holocaust', on our site: "In his writings and discussions on the subject, the Rebbe rejected all theological explanations for the Holocaust. What greater conceit — the Rebbe would say — and what greater heartlessness, can there be than to give a "reason" for the death and torture of millions of innocent men, women and children? Can we presume to assume that an explanation small enough to fit inside the finite bounds of human reason can explain a horror of such magnitude? We can only concede that there are things that lie beyond the finite ken of the human mind. Echoing his father-in-law, the Rebbe would say: It is not my task to justify G‑d on this. Only G‑d Himself can answer for what He allowed to happen. And the only answer we will accept, said the Rebbe, is the immediate and complete Redemption that will forever banish evil from the face of the earth and bring to light the intrinsic goodness and perfection of G‑d's creation."