'Flint' in the Bible

Then Zipporah took a flint, and cut off the foreskin of her son, and cast it at his feet; and she said, "Surely you are a bridegroom of blood to me."

who led you through the great and terrible wilderness, [in which were] fiery serpents and scorpions, and thirsty ground where there was no water; who brought you forth water out of the rock of flint;

At that time, Yahweh said to Joshua, "Make flint knives, and circumcise again the children of Israel the second time."

Joshua made himself flint knives, and circumcised the children of Israel at the hill of the foreskins.

who turned the rock into a pool of water, the flint into a spring of waters.

whose arrows are sharp, and all their bows bent. Their horses' hoofs will be like flint, and their wheels like a whirlwind.

For the Lord Yahweh will help me; therefore I have not been confounded: therefore have I set my face like a flint, and I know that I shall not be disappointed.

As an adamant harder than flint have I made your forehead: don't be afraid of them, neither be dismayed at their looks, though they are a rebellious house.

Yes, they made their hearts as hard as flint, lest they might hear the law, and the words which Yahweh of Armies had sent by his Spirit by the former prophets. Therefore great wrath came from Yahweh of Armies.