《资治通鉴·唐纪·唐纪十四》
于是太子每隔一日便在东宫处理政务，事情一毕就进入皇宫侍侯太宗服药用饭，不离身边左右。
于是太子间日听政于东宫，既罢，则入侍药膳，不离左右。
Thus, every other day, the Crown Prince handled official duties in the Eastern Palace. Once he was finished, he would enter the imperial palace to attend to Emperor Taizong’s meals and medication, staying close by his side.