‘Abdullaah ibn Ja‘far At-Tayyaar, May Allah Be Pleased with him, once entered an orchard of palm-trees. There, he saw a young black slave guarding the orchard. Then the slave brought his food, three pieces of bread. Along came a hungry dog and the slave gave it a piece of bread; it hastily ate it. The slave then threw the second and the third pieces of bread, which the dog ate. ‘Abdullaah ibn Ja‘far, May Allah Be Pleased with him, was looking at him and he then asked: “Was that your food for today?” The slave replied: “Yes.” “Why did you give it to that dog?” asked ‘Abdullaah, May Allah Be Pleased with him. The salve said: “This dog does not live in this area. It came from a far distance and it is very hungry and I hated to fail it.” “What are you going to eat then?” asked ‘Abdullaah, May Allah Be Pleased with him. “I will remain hungry that day,” replied the slave. ‘Abdullaah, May Allah Be Pleased with him, then said to himself: “People criticize me for being too generous, but he is more generous than me!” Then ‘Abdullaah, May Allah Be Pleased with him, bought the orchard and the slave and then freed the slave and gave him the orchard.
The slave then said: “If this orchard is for me, then I give it for the Sake of Allah The Almighty.” ‘Abdullaah, May Allah Be Pleased with him, was astonished by that great behavior and remarked: “Should he be generous to that extent while I withhold. This will never be!”
[Al-Mustatraf]

This is competition in doing what is good and righteous. That boy was a slave and his generosity was a reason behind setting him free. He was a role model for others.

Although ‘Abdullaah ibn Ja‘far, May Allah Be Pleased with him, was known for generosity and giving, that boy was more generous and giving than him. Although he had only three pieces of bread as his food, he generously gave them to that dumb animal. He was in need for these pieces of bread but his willingness to receive the reward from Allah and his love for doing what is good urged him to give all his sustenance. Therefore, he was a true example of the righteous believer who relies upon Allah and does good often. Allah The Almighty, hence, Rewarded him in this world by granting him freedom and wealth. The slave then met that with verbal and practical thankfulness to Allah by giving away the orchard for the Sake of Allah.

This is the noble competition. The believers should compete with each other in such fields.

Allah Says (what means): {Never will you attain the good [reward] until you spend [in the Way of Allah] from that which you love. And whatever you spend - indeed, Allah Is Knowing of it.} [Quran 3: 92]

The Messenger of Allah said: “Every day two angels come down from Heaven and one of them says, ‘O Allah! Compensate every person who spends in Your Cause,’ and the other (angel) says, ‘O Allah! Inflict loss upon every miser.’” [Al-Bukhari and Muslim]