Masechet (tractate) Menachot, Perek (chapter) Yud Gimel (thirteen), Mishnah Yud Aleph (eleven)—the last Mishnah in the Masechet. Mishnah says, it says, with an animal olah (burnt offering), a fire offering a pleasant smell for Hashem. With a bird olah, it also says, a fire offering a pleasant aroma, a pleasant smell. And with a minchah (meal offering), it says, a fire offering a pleasant smell.
So it says that all of these three types of korbanot (offerings), the Behemah (animal), which is the most expensive and the highest level, with a bird, which is the middle level, and then with a minchah, which is the cheapest level. This is to teach us that the less expensive bird olah and the least expensive minchah offering, we're using the same term of Isheh Reiach Nichoach (a fire offering a pleasant smell) as the animal olah. This is to teach us that whether somebody wants to bring a lot or wants to bring a little, everything is equal in the eyes of Hashem as long as a person's kavanah (intention) and thoughts are directed toward heaven. If somebody doesn't have the ability to spend a lot and has to go with a cheaper korban (offering), it shows us that it's beloved in the eyes of Hashem. When it comes to the effort put forth, as long as we're doing our best, as long as we're trying our hardest, Hashem accepts our avodah (service). He accepts the small gift that we bring as if it's a large gift, if that's within the best of our ability. Of course, if somebody has the ability to bring the more expensive one, they should. The lower-quality one would not be as pleasing in the eyes of HaKadosh Baruch Hu (the Holy One, blessed be He) as the better one. Here we're talking about somebody who can't afford it. If you have the ability to do this, do that, and it's beloved by Hashem, in unimaginable ways, in ways that as if the wealthy person who brought the most expensive one, if a person who's poverty-stricken, he brings the lowest level one, the minchah one, it's fully accepted by Hashem, and it brings a pleasant smell to HaKadosh Baruch Hu. So that's the idea: as long as the kavanah and a person's thoughts are in the right place, Hashem accepts him with his arms fully open, 100%. Baruch Adonai Le'olam, Amen V'Amen (Blessed be Adonai forever, amen and amen). Selik Masechet Menachot (the tractate Menachot is completed).