these Persians // -wa alone at the end of a line

In Arabic wa- is a prefix, not a word of its own:

Since in Persian it is a separate word, Persian calligraphers (and Indian ones too) treat the Arabic prefix as a word that can stand at the end of a line ‒ instead of standing at the start of the next line (prefixed to the "main part" of the word:
Here pages from the bestseller from the time before the Khomeini revolution:

(pay attention to the omen above on the right and to wa- at the end of the last but fifth line)
and one from the imperial reprint of that period:

(sixth line)