The determiners da (SG) and den (PL) function as definite articles but, on the one hand, they are not always present in definite contexts, and, on the other hand, they can have demonstrative force.
Source: Weygandt 1798: 122
Source: van Dyk ca. 1765: 87
Source: van Dyk ca. 1765: 108
Source: van Dyk ca. 1765: 87