Referring to the final scene of the movie Scarface. Tony Montana calls out Sosa before he guns down enemies (like a boss). Note that he is stating his love for Tony not Sosa. Keef adds himself to the long list of rappers who have referenced Scarface.
This could also be referring to a Chicago legend, baseball player Sammy Sosa. Sosa actually played for both Chicago teams, the White Sox and the Cubs
Note that Keef’s original, no-longer-used Twitter handle, “CampaignSosa300”, is also a Sosa reference
He also boasts his support for Sosa with a tattoo on his left arm