We are going to move aside to a series of characters related to 耳 before we get back to that of 门 | 門.
Our character today is 取, which is composed of 耳 and 又. As we have learnt before, 又 is a drawing of a hand. So 耳 with 又 means "ear with a hand". What does that mean?
To understand it, we need to know some rewarding rules of ancient army in China. Soldiers shall cut one ear of the enemy he killed in a battle and take it as the proof of his military credit. With those ears, general of the army then know how much reward should be credited to him. That is how 取 was created. 取 originally means "using hand to grab an ear".
Now we know that 取 means take, get or grab. for example 取得.
It is somehow understandable even without above background knowledge, but with below picture instead:
To confirm our understanding, let us examine its evolution history (image taken from: http://vividict.com)
|Learn one Chinese Character a day - 取|
While its Bronze Script made it clearer that its right part is a hand - . It followed the same pattern to its current form - 取.
Below is a Chinese calligraphy with 取 inside for us to enjoy: