C. F. Keil and Franz Delitzsch on Genesis 35:8

Gen 35:8

There Deborah, Rebekah’s nurse, died, and was buried below Bethel under an oak, which was henceforth called the “oak of weeping,” a mourning oak, from the grief of Jacob’s house on account of her death. Deborah had either been sent by Rebekah to take care of her daughters-in-law and grandsons, or had gone of her own accord into Jacob’s household after the death of her mistress. The mourning at her death, and the perpetuation of her memory, are proofs that she must have been a faithful and highly esteemed servant in Jacob’s house.