“For I was hungry, and you gave me to eat; I was thirsty, and you gave me drink; I was a stranger, and you took me in; naked, and you clothed me; I was sick, and you visited me; I was in prison, and you came to me.”
The reason for His verdict is given. It lies in what they have revealed themselves to be (compare especially Isaiah 58:7; Ezekiel 18:5-9). They have revealed their love for Him by how they have behaved towards ‘His brothers'. By their behaviour they have revealed that they are true sons of their Father (Matthew 5:42-48). Compare Acts 9:1; Acts 9:4-5 for this idea that what people do to Jesus' disciples is done to Him, because they are a part of Him (John 15:1-6; John 17:20-21; 1 Corinthians 12:12 onwards).
There is an interesting parallel in the Egyptian Book of the Dead, ‘I have given bread to the hungry, water to the thirsty, clothes to the naked, a ferry boat to the boatless'. But these are the more obvious needs of the poor, and together with hospitality, were widely practised (Romans 12:13; 1 Peter 4:9). It is the other two which are more distinctive and are very much seen as Christian responsibilities (see Hebrews 13:2-3; James 5:14; Acts 28:8; but see also Sir 7:35). Nevertheless the whole was a reminder by Jesus of the future that many of His people would face.
As mentioned above this behaviour parallels God's behaviour towards His own in the Old Testament. Thus by doing this they are being perfect even as their Father in Heaven is perfect (Matthew 5:48). It also parallels the behaviour of God's Coming One (Isaiah 35:5-6; Isaiah 42:6-7; Isaiah 49:6; Isaiah 49:10; Isaiah 61:1-3), thus making them like Himself.
We can compare how this epitomises the early church as seen in the book of Acts 2:45; Acts 4:34 where food, drink and clothing was ensured for all by the sacrifices of some among them, because they had first ‘believed' (Acts 2:44; Acts 4:32). And that would also soon develop into prison visiting, which would be very necessary because prisoners depended on outsiders to provide their food (Acts 8:3). It could, however, be very dangerous, especially in times of persecution, for it associated the visitor with the prisoner. The reception for strangers was important because there were few inns, but Christians became famed for their hospitality.