Those that escape war and famine (Job 27:14) shall be buried by the deadly plague - “death” (Job 18:13; Jer 15:2; Rev 6:8). The plague of the Middle Ages was called “the black death.” Buried by it implies that they would have none else but the death plague itself (poetically personified) to perform their funeral rites, that is, would have no one.
his - rather, “their widows.” Transitions from singular to plural are frequent. Polygamy is not implied.