Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

In the anticipation of such a future, those who inwardly participate in the present sufferings of Zion are to rejoice beforehand in the change of all their suffering into glory. "Rejoice ye with Jerusalem, and exult over her, all ye that love her; be ye delightfully glad with her, all ye that mourn over her, that he may suck and be satisfied with the breast of her consolations, that ye may sip and delight yourselves in the abundance of her glory." Those who love Jerusalem (the abode of the church, and the church itself), who mourn over her (hith'abbēl, inwardly mourn, Sa1 15:35, prove and show themselves to be mourners and go into mourning, b. Mod katan 20b, the word generally used in prose, whereas אבל, to be thrown into mourning, to mourn, only occurs in the higher style; compare ציּון אבלי, Isa 57:18; Isa 61:2-3; Isa 60:20), these are even now to rejoice in spirit with Jerusalem and exult on her account (bâh), and share her ecstatic delight with her ('ittâh), in order that when that in which they now rejoice in spirit shall be fulfilled, they may suck and be satisfied, etc. Jerusalem is regarded as a mother, and the rich actual consolation, which she receives (Isa 51:3), as the milk that enters her breasts (shōd as in Isa 60:16), and from which she now supplies her children with plentiful nourishment. זיז, which is parallel to שׁד (not זיו, a reading which none of the ancients adopted), signifies a moving, shaking abundance, which oscillates to and fro like a great mass of water, from זאזא, to move by fits and starts, for pellere movere is the radical meaning common in such combinations of letters as זא, זע, רא, Psa 42:5, to which Bernstein and Knobel have correctly traced the word; whereas the meaning emicans fluxus (Schrder), or radians copia (Kocher), to pour out in the form of rays, has nothing to sustain it in the usage of the language.