Span is an older strong past tense form of spin — this is the past tense form that existed in the older Germanic ancestors of English. In German, for example, the past tense of spinnen is still spann. In English, span has mostly fallen out of use in favor of spun for both the past participle and simple past forms. This is a form of paradigm leveling. It has occurred in other words like sting (no stang) but not in ring (where we do have rang).
The OED actually gives your quote as follows:
When Adam dalve, and Eve span, Who was than a gentle~man?
Note that this quote is dated from 1560. At this time, span was a more common past tense form, and of course well-known quotes are usually more resistant to being updated to modern vocabulary and grammar. (Interestingly, it looks like dalve has been out of use long enough by now that, at least where you read it, it was updated to delved.)
The OED cites uses of span dating up to the late 19th century, for example, this quote from 1882:
In bad weather she sat at home and span.
So, your answer is: if this sentence were constructed today, then spun would be the correct word, as you suspect. This is simply an old quotation where that word remains fossilized.
Adjourn has two meanings. It can mean to interrupt a meeting with the intention of resuming later, but it can also mean to move.
Your quoted sentence could be written as
The meeting will be moved from time to time and from place to place.
Or even clearer
The meeting time and place will change.
Best Answer
It is a poetic way of replacing the word work in a gender-specific way. To wit:
When the quotation says that Adam delved, it is saying that he delved into the soil of the earth he farmed; this illuminates the connection with the primary meaning of delve. In other words, it is another way to say that he tilled the soil, an old male-specific metaphor for general work in English.
When it says that Eve span, it is similarly referring to a female-specific metaphor for work; not so long ago, women were largely responsible for tailoring and mending the clothing of their household, and even today hobbies like crocheting and knitting are strongly associated with the feminine sex. Weaving cloth in those days would have required a distaff and a spindle; a spindle is a weighted object that spins as it releases cloth to the loom, which explains the use of the participle span.
Though you didn't ask about it in your question, gentlemen had less of a vague meaning than today, where it can be applied to just about anybody, rich or poor; back then, in John Ball's time, to have been called a gentleman would have been to be a man of means, of good family and distinction, and it would connote more of a class divide than we observe with the word today. Indeed, gentlemen has a shared etymological root with the word gentry, which as you'll note still retains that distinction for scholarly use.
So in other words, the quotation can be crudely paraphrased thus:
That massage would have soundly resonated with the rebels of the Peasant Revolt John Ball was preaching to.