The literal translation of the verse is, “It is easier for a camel to pass through the eye of needle”.
In Jerusalem there were many gates that one could use to enter the city. One of the gates was known as the eye of the needle. Because it was low to the ground, any camels who approached through the gate would have to get down on their knees and bow down their heads. It was not impossible to get through, but it took effort. For Jews of the day, they would have understood that a person of wealth or someone who was held in high esteem in this world would have to bow down and get on his knees, (humble himself) to enter heaven. Just as the camel would still be a camel after he passed through the eye of the needle, a rich man could still be rich, but humble before God.