In Middle English, -eth was a possible plural verb ending, as well as a third-person singular verb ending. The form of plural verbs varied by dialect. See the following page, “present tense” column “south”:

 https://www.ling.upenn.edu/~kroch/courses/lx310/handouts-09/MiddleEnglishVerb.html

Or the verb table on this Wikipedia page: https://en.m.wikipedia.org/wiki/Middle_English

The “th” sound is represented by the letter “thorn” there: -eþ.

I don’t know if that is the reason for the usage on the inscription.

In Middle English, -eth was a possible plural verb ending, as well as a third-person singular verb ending. The form of plural verbs varied by dialect. See the following page, “present tense” column “south”:  Middle English Tense Inflection.

Or the verb table on this Wikipedia page.

The “th” sound is represented by the letter “thorn” there: -eþ.

I don’t know if that is the reason for the usage on the inscription.

Yes, -eth was a possible plural verb ending in Middle English. See the following page, “present tense” column “south”:

https://www.ling.upenn.edu/~kroch/courses/lx310/handouts-09/MiddleEnglishVerb.html

Or the verb table on this Wikipedia page: https://en.m.wikipedia.org/wiki/Middle_English

The “th” sound is represented by the letter “thorn” there.

I don’t know if that is the reason for the usage on the inscription.

In Middle English, -eth was a possible plural verb ending, as well as a third-person singular verb ending. The form of plural verbs varied by dialect. See the following page, “present tense” column “south”:

https://www.ling.upenn.edu/~kroch/courses/lx310/handouts-09/MiddleEnglishVerb.html

Or the verb table on this Wikipedia page: https://en.m.wikipedia.org/wiki/Middle_English

The “th” sound is represented by the letter “thorn” there: -eþ.

I don’t know if that is the reason for the usage on the inscription.