Jamieson, Fausset & Brown, on Lam 2:18

“Sade. Their heart cried to the Lord upon the walls of the daughter of Sion: Let tears run down like a torrent day and night: give thyself no rest, and let not the apple of thy eye cease.”

“wall-- (Lam 2:8). Personified. "Their heart," that is, the Jews'; while their heart is lifted up to the Lord in prayer, their speech is addressed to the "wall" (the part being put for the whole city). let tears, &c.-- (Jer 14:17). The wall is called on to weep for its own ruin and that of the city. Compare the similar personification (Lam 1:4). apple--the pupil of the eye (Psa 17:8).”

Imported from an open dataset — not yet checked against the printed edition.