Dahhh say that shit basically means just kidding.
Here's an example:

Man I fucked your sister the other day, Dahhh say that shit.

Hey bro I'm about to vote for Donald trump, Dahhh say that shit.

Man I'm a crip and a blood, Dahhh say that shit.

Man she ugly then a hoe but got a fat ass, Dahhh say that shit.
by Skurrr214 September 28, 2015
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