And his sons Isaac and Ishmael buried him in the cave of Machpelah, in the field of Ephron the son of Zohar the Hittite, which is before Mamre;

Wesley's Notes

25:9 Here is nothing recorded of the pomp or ceremony of his funeral; only we are told, his sons Isaac and Ishmael buried him - It was the last office of respect they had to pay to their good father. Some distance there had formerly been between Isaac and Ishmael, but it seems either Abraham had himself brought them together while he lived, or at least his death reconciled them. They buried him, in his own burying - place which he had purchased and in which he had buried Sarah. Those that in life have been very dear to each other, may not only innocently, but laudably, desire to be buried together, that, in their deaths, they may not be divided, and in token of their hopes of rising together.

Jamieson-Fausset-Brown Bible Commentary

9, 10. his sons . buried him-Death often puts an end to strife, reconciles those who have been alienated, and brings rival relations, as in this instance, to mingle tears over a father's grave.

Matthew Henry's Concise Commentary

25:1-10 All the days, even of the best and greatest saints, are not remarkable days; some slide on silently; such were these last days of Abraham. Here is an account of Abraham's children by Keturah, and the disposition which he made of his estate. After the birth of these sons, he set his house in order, with prudence and justice. He did this while he yet lived. It is wisdom for men to do what they find to do while they live, as far as they can. Abraham lived 175 years; just one hundred years after he came to Canaan; so long he was a sojourner in a strange country. Whether our stay in this life be long or short, it matters but little, provided we leave behind us a testimony to the faithfulness and goodness of the Lord, and a good example to our families. We are told that his sons Isaac and Ishmael buried him. It seems that Abraham had himself brought them together while he lived. Let us not close the history of the life of Abraham without blessing God for such a testimony of the triumph of faith.