When did Mourad come to Aram's house? Why?

Mourad visits his cousin Aram’s house at 4:00 a.m, one summer day. At the time, Aram is only nine years old. Mourad knocks at Aram’s window to wake him up. He has a “beautiful white horse” which he would like to ride with Aram. Aram does not understand how his cousin has come by the horse for he knows that they are too poor to afford one—the whole tribe is “poverty-stricken.” He guesses that his cousin has most likely stolen the horse, and this shocks him for the whole Garoghlanian family holds fast three qualities: “Pride, honesty, and a belief in right and wrong.”
He debates in his mind on whether to accept Mourad’s invitation to ride a stolen horse. He concludes that “stealing a horse for a ride” differs from stealing a horse to sell, for money. It seems as if he compares the two in terms of which is a greater wrong, and decides that the latter is. He therefore hurriedly dresses up and joins Mourad for the ride. After the ride, the two boys hide the horse in an abandoned vineyard as it is already daylight and they cannot return the horse back to its home. Later on, Aram discovers that Mourad has been keeping the horse for about a month and that the horse’s owner is an Assyrian neighbor, called John Byro. He convinces his cousin to hold on to the horse until he learns to ride it. The two boys keep the horse for two more weeks, and then finally return the horse to its owner.

If we look at the first paragraph of the story, we learn that Aram was around nine years old when his cousin, Mourad, came to his house. It is about four o'clock in the morning when Mourad arrives, and it is only barely light outside.
The reason that Mourad has come to Aram's house is that he has stolen a horse from a local farmer, John Byro. Mourad wants to let Aram have a go at riding the horse. Mourad has had the horse for some time already and is already very skilled in horseriding.
When Aram sees the horse outside, he thinks he's dreaming because he knows that Mourad could not afford to buy his own horse. However, he is not concerned by the fact that the horse is stolen. He just wants the chance to ride it.