A prophet’s reward entails being called righteous, like the prophets, who represented divine righteousness (Matthew 5:10), and the disciples’ calling was similar to that of the prophets (Matthew 5:12). Those who receive the prophets share in their ministry and its rewards. There are different degrees of reward (Matthew 5:12, Matthew 5:19; Matthew 6:20), but God values all those who show hospitality to the disciples.
The task and calling of the disciples is very similar to that of the prophets (Matthew 5:12). They are called righteous because they represent divine righteousness (Matthew 5:10). Those who receive the prophets as righteous thereby acquire a share in the ministry and as such are rewarded. A distinction in the degrees of reward that each one receives is assumed here (see also Matthew 5:12, Matthew 5:19; Matthew 6:20). Jesus wants the disciples to know how greatly God values the hospitality shown to them.1
41 The one who receives a prophet because he is a prophet will receive a prophet’s reward, and the one who receives a righteous person because he is a righteous person will receive a righteous person’s reward.