Luther comments on the deep sorrow of Rachel, barren many years, and how despair drives her to sobbing, sighing prayer:

Therefore Moses has employed a significant word: “The Lord remembered.” It is as though he were saying: “She had almost despaired within herself, and she was convinced in her heart that God would never remember her, yes, that He had forgotten her forever.” “I shall not be a mother,” she thought, “but I am the most wretched of all women. I should have been the mother of the house, but God has forgotten me.” In this way she was led down into hell, where no hope of help seems to be left. In despair she takes hold of her maidservant and hands her over to her husband, which she would not have done if she had not given up all hope. Yet she despairs in such a way that she retains a spark of faith. In her despair she retains that sobbing which Paul calls ineffable (cf. Rom. 8:26), but this is so deeply buried and covered with impossibility and contrary emotions of the heart that she is barely conscious of that sobbing or sighing.

-AE 5, on Genesis 30:24