Targum Pseudo-Jonathan on Exodus 40:6 gives the outer altar a location and a purpose that the plain Hebrew leaves unspoken. Place it before the door of the tabernacle of ordinance, the meturgeman says — because the rich, who spread the table before their doors and feed the poor, shall have their sins forgiven what time they make the offering upon the altar.
The altar and the front door
The altar of burnt offering stood outside, at the entrance of the sanctuary, where anyone approaching had to pass it. The meturgeman sees a pattern. The rich man's own front door is supposed to look the same way. Anyone approaching a rich Israelite's home should be able to see a table set, a plate filled, and a place reserved for whoever is hungry.
Hospitality, in the meturgeman's reading, is architecture. A righteous rich household is not one that happens to give charity occasionally. It is one whose front door is designed to welcome the poor, the way the sanctuary's front is designed to welcome the offering.
A sacrifice that forgives
Here is the promise. When such a rich person brings an offering to the altar of the sanctuary, the meturgeman says, their sins shall be forgiven. The forgiveness is not earned by the sacrifice alone. It is earned by the continuity between the sanctuary altar and the altar of one's own table. A person whose home is already a place of feeding the poor arrives at the sanctuary altar carrying habits that match the altar's purpose.
The ancient sages extended this into later Jewish practice. The table in every Jewish home, they taught, functions like an altar. Bread is broken with salt, as sacrifices were salted. Guests are welcomed. The poor are not an afterthought. When the Temple was destroyed, this idea became urgent: with no altar standing, the home's table had to carry the sanctuary's weight.
The takeaway: wealth is forgiven by hospitality. The altar stands at the door because the door is where forgiveness begins.