You are the salt of the earth. The disciples are likened to salt, because they are valuable. In Jesus' time, salt was a valuable commodity. Roman soldiers were sometimes paid with salt, hence the expression 'worth their salt'. In addition, salt is also used for processing food, both to enhance its delicious taste and to preserve it. Likewise, the role and function of the disciples in the midst of the world. They are called and sent for a service that improves the quality of life on earth and prevents decline. The importance of the mission is emphasized by highlighting the opposite, if salt is not delicious, for example because it is mixed with other minerals, it cannot be used properly and must be thrown away. The words 'thrown away' and 'trodden on' are the language of judgment, meaning that people who do not do God's will for the good of the world will face judgment.

The disciples as the light of the world, remind us of the servants of God who are lights for the nations (Isaiah 42: 6, 49: 6). Does this statement of Jesus, together with the metaphor of the salt of the earth, refer to the mission of the disciples to go to all nations (Matthew 28:19)? The additional metaphor of the ‘city on a hill’ which reflects the situation of Palestine with its cities on the tops of the hills, does not suggest the departure of the messengers to all nations, but describes a community/congregation that has an appeal to the whole world. The combination of the words light, world, city, and mountain reminds of the eschatological prophecy of the prophet Isaiah (Isaiah 2:2-5), about the ‘mountain’ of the Temple and the ‘city of Jerusalem’ that attracts the nations to study the Torah. This means that this can be an invitation for Israel to walk in the ‘light’ of the Lord. The role of Jerusalem as the ‘city of light’ that attracts the nations, is here transferred to the Christian congregation that wants to attract all nations to the light of the Lord. Oil lamps or lamps are usually placed on high lampstands, and their light is enjoyed by everyone in the house which may only be in one room. Likewise, the whole world received God's light if the disciples did not hide it, but shone the light that God gave them. Putting a lamp under a jar sounds very strange, but it represents a real choice. Remember the servant who hid his old talents in the ground (Matthew 25: 18-20).