Theory:

     He smiled at the unfriendly face, then pointed to his ears and shook his head from side to side. A quick look of surprise changed the man’s face as he studied the notepad, then turned and said something to his friend.
 
     Ray used the chance to look closely at the man, paying attention to the shape of a gun and a restless hand in the man’s right coat-pocket. Anger boiled within him, but it was kept down by an inner voice that said, “Be still.” He wrote on the notepad, “May I help you?” For the first time the older man looked directly at Ray and smiled. A cruel, mocking smile. They both understood why he was there, why his friend remained at the door. They looked like men who were down on their luck, and were now ready to try something they would later be sorry about.
 
     The clocks ticked on. Ray calmly wrote another message. “Have you come to pick up a clock or watch?” Then he pointed to the ‘loan’ board filled with hanging clocks and pocket watches. He was not a pawnbroker, but at the same time couldn’t say ‘No’ to the needy people who placed their old watches or clocks before him for anything they could get. He loaned more than he should. They would be there when the owners wanted them back… at the same price he had paid, with no interest.
Explanation:
  
After pushing the notepad and pencil across the counter, Ray looked at the older man and smiled. The latter's face was still unfriendly. He then pointed to his ears and shook his head from side to side, trying to tell the man that he was deaf.
 
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Ray conveyed to the man that he was deaf
 
The man looked surprised, then looked at the notepad and the pencil. He realised that Ray was deaf. He then turned to the younger man at the door and said something.

Now, the lesson doesn't reveal what the man had spoken. This is an important feature because the author doesn't give us any details that Ray doesn't have. We see the story through the eyes of Ray, and we sense what he can sense. Nothing more and nothing less.

Though we do not know what was spoken, he might have explained Ray's disability to the other guy. Moreover, there are chances that he said something about how it is easier for them to steal from Ray, given that he is deaf.

So, back to the lesson, when the men communicated, Ray took his chance to observe the older man. He could trace the shape of a gun in the man's right coat-pocket. The man also had his hand in the pocket, restless and ready to act.
 
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Man had a gun in his right coat-pocket

Ray's fear turned into anger. He was in rage, but his inner voice told him to be still and calm. Ray took his notepad and wrote on it: “May I help you?” The man read it, then looked at Ray and smiled. However, the smile wasn't a nice one. It was a cruel, mocking smile.
 
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The man gave a cruel mocking smile

The man understood that Ray knew why the man was there and why his friend remained at the door. They looked like men who had lost all their ways and hopes. They probably tried living the lives of genuine people, but nothing good might have come out of it. So, tired of being good, and tired of being poor, having lost all hopes, they were ready to do something wrong.
 
The clocks in the shop ticked on. Time passed by, and the man was yet to respond on the notepad. Ray remained calm and wrote yet another message: “Have you come to pick up a clock or watch?” It was a natural question, one that Ray is likely to ask his customers. Though Ray knew that the men had no intention of buying or pledging anything, he wrote the message to communicate further. After writing the question, he pointed to a board filled with hanging clocks and pocket watches. It was the 'loan board'. So Ray asked the man whether he had come to pick up the item that the latter had pledged. But in reality, he was trying to show the man that he need not resort to bad means to get money; he can get a loan instead.

Though Ray was not a pawnbroker, he gives out money to the needy people as loans. When the needy approach him for money in return for their items, he pays them the money they need, even if they are not worthy.
 
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Ray loaned money to the needy
 
Ray was a generous man, for he pays more than the items deserve. Moreover, he never charges interests for the money he loans out, and he keeps the things safely until their owners come back to retrieve them. He was quite the opposite to Shylock, the most famous (or rather, infamous) moneylender in the history of English literature.

So one may wonder why Ray took their items in exchange for his money, and not merely give the money to the needy. The answer is simple: Ray does this to make people feel less bad about themselves. He doesn't want people to lose their self-esteem or feel indebted. Ray was not only generous and kind but was also thoughtful.
 
Meanings of difficult words:
 
S.No
Words
Meanings
1
RestlessUnable to rest or relax as a result of anxiety or boredom
2
MockingMaking fun of someone or something
3
Down on their luckExperiencing a period of bad luck
4
LoanAn act of lending something that is expected to be paid back
5
PawnbrokerA person who lends money at interest on the security of an article pawned
6
InterestMoney paid regularly at a particular rate for the use of money lent
Reference:
National Council of Educational Research and Training (2006). The Old-Clock Shop (pp. 11-14). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.