Musannaf Ibn Abi Shaybah

Qabeesah bin Dhu’ayb says that a plague broke out in Syria, so much so that in some households, every single member would die. Hazrat Umar (may Allah be pleased with him) wrote that the one above should be made the heir of the one below, and if that is not possible, then they should be made heirs of one another. Sa’eed says that the meaning of making the one above the heir of the one below is that among them, the one who died would die in such a way that his hand would be placed on the side of the other.