To illustrate what we mean by that, consider what happens when someone tells you how to do something moderately complicated with a certain computer program (say, MS-Word or Excel). They tell you how to work it, but that day you don't operate it yourself (maybe they were telling you over the phone when you weren't at a computer). When you finally try it yourself the next day, you can't get anything to work. All sorts of crucial details are missing from your memory. Or perhaps you remember everything perfectly, but they forgot to tell you something crucial. Now consider what happens when someone sits down in front of you and demonstrates how to operate the program. They run through the whole thing and explain as they go. The next day, you try it yourself for the first time. And barely anything works, again because crucial details are missing. And now consider what happens when they show you how to work the program by having you sit down at the computer. You type as they tell you what to do and point things out on the screen. Every time they forget a detail, you catch it immediately, and they supply the missing info. Every time you run into something you don't understand, you just ask them right away, or they tell you without your asking because it's obvious what you need to be shown. When you work the program again the next day, you're not a pro yet, but you can actually do stuff.
What's relevant here is not the sense of touch, but whether you are actively engaged with the tool. When you interact with the tool using your very own body, the reality of the tool becomes known to you in a different way than when someone tells you or shows you how to use the tool. You understand in a right-brain way rather than a left-brain way. The reality of the tool is guaranteed to have shown itself, because you had a concrete experience with the tool, not just a verbal or symbolic representation of it. The causal relationships of the tool get burned into your brain in a way that transcends words. You could try to translate your understanding into a linear stream of words, but you would indeed be translating: the actual knowledge that you have is not linear and not words. It's an "all at once" thing, and it seems that the knowledge resides in your hand. Or in other words, you have come to understand the tool in the Ti way.