This hadith has been narrated on the authority of Aswad b. Qais with the same chain of transmitters, but herein no mention has been made of the other month (consisting of) thirty days.
Sahih Muslim Book 13, Hadith 18
← Previous Hadith We are an unlettered people who can neither write nor count. The month is thus, and thus. folding his thumb when he said it the third time.

Sahih Muslim Book 13, Hadith 17 Next Hadith → This night is the midnight (of the month). Upon this he said to him: How do you know that it is the midnight (of the month), for I heard the Messenger of Allah (ﷺ) as saying: The month is thus and thus (and he pointed with his ten fingers twice) and thus (i. e. at the third time he pointed with all his fingers but withdrew or folded his thumb)?

Sahih Muslim Book 13, Hadith 19