Mailman finds my bud

So... as it goes earlier today my dude hits me up asking if I would like a quarter of some stellar bud. I say yes (ofcourse) and since I wasn't home at the time and my dude living relatively close and him always delivering I asked him to put it in my mailbox and I'll get the money to him later in the day. He agrees and text me saying he put it in my mailbox and with no mail being in it. Thinking I'm good since it's later in the day and assuming the mailman already delivered and my mother or sister grabbed the mail first I thought nothing of it. I happily drive up to my mailbox after errands and immediately panic. Right there is my sack sitting right on top of newspapers and other mail. I'm currently freaking out a little and don't know what I should do. Any advice would help!