The Hebrew verb ul means to suckle or to nurse, used of a mother nursing a child. Its related noun refers to a suckling infant or nursing child. This word appears in some of Scripture's most tender and theologically potent passages, where the nursing mother-child relationship becomes an image of divine care.
Isaiah 49:15 deploys ul in one of Scripture's most powerful rhetorical questions: 'Can a mother forget the baby at her breast (ulah)... I will not forget you!' God's love is measured against — and declared greater than — the most intimate human bond. The nursing infant represents total dependence; God's response is total faithfulness.