They were talking about calcium. But let's plug some iron sources into cronometer:

- 100g lentils: 3.3mg iron, 116cal

- 100g spinach: 2.7mg iron, 23cal

- 100g cooked tofu: 2.7mg iron, 110cal

That's more than 50% of the day's iron recommendation for women in about 250 calories or about 1/8th of the day's calories for the average woman.

100g is a large volume of loose spinach and dry lentils. That's a hearty entree for a hungry lass once cooked.

That's 100g of cooked lentils and 100g of raw spinach. 100g of raw spinach cooks down to about the size of a deck of cards.

Though I don't see the point of quibbling here. My point only gets stronger and stronger as I add in more foods and calories, even packaged grain foods that are incidentally fortified with iron.

Isn't iron in spinach insanely difficult for humans to actually absorb? Quick googling says it's around ~2% of total iron in spinach which we can absorb, so instead of eating 100g to get 2.7g you'd need to eat 5kg of spinach per day.

The topic every vegan refuses to discuss:

Biolavailability

That might be the recommendation for a very small woman.

For men of average size, the recommended daily intake of iron varies between countries, but it can be as large as 14 mg, which would need at least 400 g of cooked lentils per day, according to your list, which corresponds to lentils cooked with an unknown amount of water, so it is difficult to compare it with lentils cooked in different ways, though it seems that these 100 g of cooked lentils correspond to about 40 g of raw lentils with about 60 g of water.