What is the scriptural basis for the Holy Spirit speaking to you through other people's words? Sometimes I get the distinct feeling that something that someone has said is working on multiple levels. On the surface level they're talking about whatever makes sense in the context of the conversation, but on another level, it feels like they are speaking to a specific thing relevant to my spiritual life.

For instance, I have a bad habit I am trying to quit. I have prayed for God's help. Some days I feel like I really don't want to quit and I fall back into the habit. Then later the same day I'll be talking to another Christian about the weather and they might mention that it's windy and I'd say, "Well, that's Texas for you." And they would reply, "Yeah, it's not going to quit."

In that instance I felt like it was the holy spirit speaking, talking about me going back into my habit even after asking for help to quit. It was saying I wasn't going to quit. Considering the wind is used many times in the Bible as a symbol of God's presence in the world it seems even more likely.

What is the biblical basis for the idea that the Holy Spirit speaks through the words of other people, even those not meant to be advice?
I do not think that there is any direct scriptural basis for God speaking through other people. This means that (to my knowledge) there is not a specific Bible verse that iterates this crystal clear.

But after close inspection, you can see that God speaks in miraculous ways. He used Balaam to speak. Even though Balaam was not a Christian, and was rebellious, God used miraculous ways to speak.

Know I know this isn't exactly the kind of situation you're talking about, but it is something to think about. God will talk to you in many different ways.

Sometimes while I'm coding, I'll listen to (christian) music as well. Twice in the course of a half-hour, the words I was typing matched with the song. And it just got me thinking, "Wow, God is amazing. He can use any method to speak." He can use any method he wants to talk to you. Dreams, other people, even sitting down in your room! Yeah, that happened. God uses amazing ways to accomplish his will. And if speaking to you is His will, it'll get done.