Commentary for Genesis 6:21

Take for yourself (or “from your own”). He was forbidden to take from others, even though everything was about to be destroyed. This would also increase the miracle since Noach surely did not possess enough to feed them all without a special blessing.

ואתה קח לך מכל מאכל, different menus for different species of creatures.

ואתה קח לך, seeing that they will come to you in order to survive, you will have to prepare food for them, each species according to the type of diet it is used to. Even the predators will not be allowed to eat flesh while in the ark but would have to subsist on a vegetarian diet. They had, after all, been used to such a diet immediately after they had been created, as we have already explained on Genesis 1,25.

מכל מאכל, “from every category of food;” seeing that the ark contained all the living creatures that consumed food, Noach had to store the kind of food that was eaten by all these various creatures. The reason was that some creatures refused to touch food that other creatures enjoyed eating.