en_tn_lite_do_not_use/jer/09/18.md

Let them hurry and sing a mournful song ... and our eyelids flow with water

Here Yahweh says what the people of Judah will say when the destruction comes. The words "us" and "our" refer to the people of Judah and does not include Yahweh. This may be written instead as a command from Yahweh to the people. Alternate translation: "Tell them to hurry and sing a song to mourn for you, so your eyes may run with tears and your eyelids flow with water" (See: rc://en/ta/man/translate/figs-exclusive)

so our eyes may run with tears and our eyelids flow with water

This describes the people crying a lot. Alternate translation: "so we will cry very hard with tears flowing from our eyes" (See: rc://en/ta/man/translate/figs-explicit)