The comma is a very useful invention, as it structures a text and gives a guidance for interpretation and that is why in modern text editions of Greek and Latin authors commas are used. The comma itself was invented in the third century BC at Alexandria by the Greek grammarian Aristophanes of Byzantium, but this comma was used to divide verses and not to structure a text. That use of the comma was introduced in the late Middle Ages. However, sometimes a comma can destroy a text rather than help the reader. I have come upon this while reading the following epigram by Martial:
"Thaida Quintus amat." "Quam Thaida?" "Thaida luscam."
Unum oculum Thais non habet, ille duos.
Thais (Greek acc. Thaida - Greek names often retain the Greek declension ) is a common name for designating women in a certain branch of trade, named after the (in)famous Greek prostitute Thais who lived during the time of Alexander the Great and actually accompanied him. She convinced Alexander to burn down the palace at Persepolis as a retribution for Xerxes' burning of the temple of Athena on the Acropolis in Athens in 480 BC.
The remainder is easy Latin, but what is the point? Is it that Thais has one eye and Quintus two? Well, let’s remove the comma, keeping in mind that Martial himself was unaware of the use of the comma. But now non habet can belong both to Thais and to ille: Thais does not have one eye and Quintus does not have two eyes. Here lies the pun. Of course Quintus has two eyes, but according to Martial, he is blind by falling in love with that one-eyed Thais! And so the placing of that comma by the editor has destroyed the whole pun, you see?