Jeremiah 15:9
She that hath borne seven languisheth: she hath given up the ghost; her sun is gone down while it was yet day: she hath been ashamed and confounded: and the residue of them will I deliver to the sword before their enemies, saith the LORD.
Seven in this verse stands for a full or complete number rather than an exact count. Here it describes a mother who has borne a complete number of children.
A person's life and strength can fail suddenly even while it is still day. The picture of the sun setting before the day is over shows how life can end prematurely. In particular it illustrates how death can overtake the young, even when many years of life appear to lie ahead.