At the beginning of chapter 5 in Parshat Vayikra, the Torah discusses specific sins that are subject to the law of what Chazal refer to as the "ascending and descending offering" (korban oleh ve-yored). In these cases, the Torah takes into consideration the financial situation of the sinner and determines his obligation accordingly. 

What are the circumstance of the sins for which the Torah permits a poor person to bring a more modest offering, a situation which has no parallel in the case of other transgressions? According to the simple meaning of the text, this provision applies in three cases, all set forth in the first four verses of chapter 5.

What is so special about these three particular situations? Why does the Torah provide special consideration for the poor specifically in these instances? In order to answer this question, we must first understand what these cases actually entail. This is not a simple task, since the interpretation of these verses generally accepted among Chazal does not, for the most part, follow the simple meaning of the text. We shall therefore first attempt to understand the simple level of the text, and afterwards try to understand why the Torah shows special consideration here.

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion