Which two sons buried Abraham in the cave of Machpelah?

Answer: Isaac and Ishmael

His sons Isaac and Ishmael buried Abraham in the cave of Machpelah, in the field he had bought, with his wife Sarah.

“His sons Isaac and Ishmael buried him in the cave of Machpelah near Mamre, in the field of Ephron son of Zohar the Hittite. This was the field that Abraham had bought from the Hittites. Abraham was buried there with his wife Sarah.”— Genesis 25:9-10 (BSB)