Ruth 1:17

where thou diest, will I die, and there will I be buried. She will not be swerved from her intention to cast her lot with that of Naomi. It was not the affection of a daughter to her natural mother nor that of a wife to the husband of her choice, but it was her love toward Naomi which had knit their hearts together. And the highest stage of the devotion which she yielded to Naomi for life was reached in the confession that she had found the God of Israel to be the true God, a fact which implied the highest unity of spirit. The Lord, Jehovah, do so to me, and more also, if aught but death part thee and me. It was an oath inviting the severest penalty on the part of Jehovah if Ruth should prove fickle in her affection and devotion.