Probably some other Djinn is bound to them or he himself is, I’d use them and see what is in there and try to figure out what went on… but only if you feel safe and fine with it. Djinns do tend to get tricky with us humans but not all of them mean bad
There isn’t anything that is inherently meaningful when it comes to your interaction with the djinn in an objective sense. If I were to give my two cents, it seems to hold more personal meaning rather than the latter.
Marid tend to specialize in various forms of magick so perhaps he gave you something that could be useful in the current path that you are on (possibly something to amplify particular abilities or spells).