Rice and lentils are shelf-stable, but "stable" isn't the same as "indefinite" — stored badly, both pick up moisture, off smells, and eventually insects. The fix is almost entirely about the container, not the food.
Move rice and dal out of their original paper or thin plastic packaging and into an airtight container as soon as you get home. Glass or heavy plastic both work; the goal is simply to keep humidity and pests out.
Keep the container somewhere cool and dark — a kitchen cabinet away from the stove, not a shelf that gets direct afternoon sun. Heat is what speeds up rancidity in lentils in particular.
A bay leaf or a few dried neem leaves dropped into the container is a common, low-effort way to keep weevils away without any chemical treatment.
