首楞嚴義疏注經 3.477

3.477

曾，則也。聽嗅嘗觸者，鼻舌二根境合始覺，故名嘗觸。覺觸，身也。覺知，意也。

'Ceng' (曾) means 'ze' (則, indeed). Regarding 'listening, smelling, tasting, and touching': the two faculties of nose and tongue become aware only when their objects join, hence they are called 'tasting and touching'. 'Sensing contact' refers to the body. 'Sensing and knowing' refers to the mental faculty.