The deep bond between the people of Israel and Jerusalem is painted through the intimate and comforting image of a mother nursing her child. Those who shared in the heavy mourning over the city are promised a direct and tangible experience of its future joy. The primary approach among commentators is that the sorrow over Jerusalem was not in vain; rather, it was a necessary step for the people to eventually witness its happiness and be nourished by its deep comforts and abundant goodness [מצודת דוד, רד״ק, צאינה וראינה].
Jerusalem is compared to a mother fully prepared to satisfy her children [שד״ל, מלבי״ם]. This maternal imagery serves as a metaphor for profound pleasure, a complete fulfillment of joy, and the absolute reversal of past grief [רד״ק, אבן עזרא]. The choice of a nursing infant carries an additional layer of meaning regarding the future state of the nation. Just as a baby finds its mother ready to provide nourishment effortlessly and without any prior preparation, the Israelites will eventually experience readily available abundance and peace. They will no longer need to toil and labor for their basic needs like food and clothing [אדרת אליהו].
As the imagery unfolds, there is a distinct progression in the level of delight. While the initial act of nursing is meant to satisfy basic hunger, the subsequent action shifts to a state where the child continues to draw nourishment not out of necessity, but for pure pleasure [מלבי״ם]. This transition is compared to a person eating rich, high-quality meat, who finds it so sweet that they continue to draw out the marrow from the bones long after their hunger is satisfied [אדרת אליהו].
The exact nature of this ultimate delight is understood in several different ways. One perspective connects this concept to constant movement, suggesting a promise of immense wealth and honor that will continuously flow into Jerusalem [רש״י, מצודת דוד, מצודת ציון]. Another approach views it as a promise of radiance, splendor, and highly desirable treasures [רד״ק, ביאור שטיינזלץ, אבן עזרא]. Other commentators maintain the physical maternal metaphor, explaining it as the very source of the nourishment, or like a small, sweet treat given to a baby purely for enjoyment [ביאור שטיינזלץ, מלבי״ם]. Finally, a related view describes this abundance as something that bursts forth naturally, much like milk that flows on its own from a completely full source [שד״ל].