The word "behold" alerts us to the introduction of the dead man into the story. Your language may have a way of doing this. AT: "there was a dead man who" (See: [[rc://en/ta/man/translate/writing-participants]])
This can be stated in active form. AT: "people were carrying out of the city a man who had died" (See: [[rc://en/ta/man/translate/figs-activepassive]])
"He was his mother's only son, and she was a widow." This is background information about the dead man and his mother. (See: [[rc://en/ta/man/translate/writing-background]])
This was a stretcher or bed used to move the body to the burial place. It did not have to be something in which the body was buried. Other translations may have the less common "bier" or "funeral couch."