《礼记·檀弓下》
客死异国，如果地主国的国君来吊，虽然身边没有亲人为丧主，但也一定要有人出来代表丧主拜谢，即令是死者的朋友、同乡、寄寓的房东也可以。
丧，公吊之，必有拜者，虽朋友州里舍人可也。
If a guest dies in a foreign country, if the head of state of the host country comes to pay condolences, even if there are no family members present to be the chief mourner, someone must come forward to represent the chief mourner and express gratitude. This could be a friend of the deceased, a fellow townsman, or even the landlord who provided lodging.