《资治通鉴·唐纪·唐纪十五》
太宗病情加重，上吐下泄，太子昼夜不离身边，有时一连几日不进食，头发有的已变白。
上苦利增剧，太子昼夜不离侧，或累日不食，发有变白者。
Taizong’s condition worsened and he suffered from vomiting and diarrhea; the prince stayed by his side day and night, and sometimes did not have food for several days, and some of his hair had turned white.