ואם לא תגיע ידו. אין אומרים לו ללוות ואין אומרים לו עסוק באומנותך יש לו (ואין לו) [שה] ואין לו צרכיו מנין שיביא קרבן [עני] ת״ל די שה. ואם לא תגיע ידו, “if he is financially unable, etc.” the Torah does not demand that he must borrow money in order to be able to atone for his unintentional sin, and it does not require that he use the products of his special skill and bring this as an offering. But if he owns a lamb, which is what is basically required of him as an offering, but he does not have money to cover his basic expenses, he does have to bring this lamb as his offering. The sages derive this rule from the Torah having written: די שה. (Sifra on that verse)
אחד לחטאת ואחד לעלה. הואיל ואין לו למזבח בחטאת העוף רק דמה שאינה אכילה לפיכך צריך להביא שנים אחד לחטאת לאכילת הכהן ואחד לעולה לאכילת המזבח, אבל כשעשיר חייב חטאת דיו בכשבה או שעירה לפי שיש ממנה הכשר אכילה לכהן והאימורים אכילה למזבח. אחד לחטאת ואחד לעולה, “one of which (the two birds) as a sin offering and the other as a burnt offering.” Only the blood of a bird offering that is a sin offering is brought to the altar, so that the altar has something that can be “eaten.” When a wealthy person has to bring a sin offering, the Torah is satisfied with either a female sheep or goat, seeing that there is enough meat on these animals to provide a meal for the officiating priest, and the entrails provide the ”meal” for the altar.