La definizione del Black's è illuminante:
Witnesseth, vb., shows, records. This term, commonly separates the preliminaries in a contract, up through the recitals, from the contractual terms themselves. Modern drafters increasingly avoid it as an antiquarian relic. Traditionally, the subject was This Agreement. This agreement witnesseth (i.e. shows or records) that, whereas---
Many modern contracts erroneously retain the Witnesseth even though a new verb appears in the preamble. After the preamble is a period, followed by an all capped WITNESSETH.
It is an example of a form retained long after its utility, and most lawyers do not know what it measn or even the purpose it once served.