The Shuzhai yehua 書齋夜話 "Nocturnal talks of the Book Studio" is a biji 筆記 "brush notes" style book written by the late Southern Song period 南宋 (1127-1279) scholar Yu Wan 俞琬 (ca. 1253-ca. 1314). He has written a lot of studies on the Confucian Classic Yijing "Book of Changes", like Zhouyi jishuo 周易集說, Du Yi juyao 讀易舉要, Yiwai biezhuan 易外別傳, and Daoist texts, like Zhouyi cantong qi fahui 周易參同契發揮, Yinfujing zhu 陰符經注 and Luhuo jianjie lu 爐火鑒戒錄, as well as the biji style books Yuexia outan 月下偶談 and Xishang futan 席上腐談, and the Yuanxue zhengzong 元學正宗, a book on philosophy. His collected writings are called Linwu shanren ji 林屋山人集.
The 4 juan "scrolls" long Shuzhai yehua is a collection of notes written down during the author's studies of ancient texts. The first part talks about the exegesis of the Confucian Classics. It is helpful because it critically comments on older scholars like Kong Anguo 孔安國 from the Tang period 唐 (618-907), and corrects many errors in the field of word interpretation (zixun 字訓). The second and third part discuss the early Confucian texts, including texts about the apocryphal charts Hetu 河圖 and Luoshu 洛書 and the origin of the Neo-Confucian charts Xiantiantu 先天圖 and Taijitu 太極圖. He shows that these charts originate in cinnabar formulas (danjue 丹訣) of Daoist writings.
The Shuzhai yehua is included in the collectanea Siku quanshu 四庫全書, Wanwei biecang 宛委別藏 and Xuanyin wanwei biecang 選印宛委別藏.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, Changchun: Jilin daxue chubanshe, vol. 2, p. 1960.