He cancelled the date saying he doesn't want to rush things: what to say

Start by comparing this message to how he's been texting before it. If he's been quick, specific, and curious, a cancel framed around not wanting to rush is more likely to be honest nerves or a real preference for slower building. If the thread has been thinning, with longer gaps and shorter replies, the phrase is more likely a polite way of cooling off. Pay attention to whether he offered any alternative. Someone who wants to keep going usually names a rough next window, even a vague one. Someone backing away often just stops at the cancellation.

Also notice what 'not rushing' implies about how he sees the two of you. Plenty of people use the phrase after meeting only once or twice, and some use it because they've been burned by fast starts. It can also mean the date you planned felt like a bigger step than he was ready for, like a dinner when he'd pictured coffee. Those are different problems. Only your next message will show you which one you're dealing with.

The reply's job is to let him clarify without feeling cornered. Acknowledge the reason in a sentence so he knows you heard it and aren't going to argue. Then make one simple move that tests intent. Suggest a lower-stakes way to keep talking, like a call, a shorter coffee, or just carrying on the conversation for now, and ask what feels comfortable to him. Keep the ask small enough that saying yes costs him almost nothing.

Be clear about your own position too, without making a speech. If you'd prefer to meet sooner, say so once in plain terms. If you're fine waiting, say that instead, but only if it's true. Don't stack a question, a compliment, a joke, and a new plan into one message. Each extra element gives him more to reply to and makes a yes or no harder to read.

After you send your reply, the most useful information is how he responds and how long it takes. A warm answer within a day or two, even an awkward one, usually means the door's open. A short reply that's still engaged, with a question back to you, is also a good sign. Give him a reasonable window before deciding anything. Two to three days is fair for a casual thread, and longer is normal if it's a weekend or he's busy.

If he doesn't answer, send one short follow-up at most, and keep it low pressure rather than a check on whether he's still interested. Then stop. If he still doesn't respond, or replies with something vague that reopens the same question, take that as your answer. Don't keep rephrasing the invitation to see whether different wording gets a different response. Moving on at that point is the sensible move, and it leaves the door open if he ever comes back with a clear plan.