Why did Jesus (as) name the coming prophet Ahmad and not Muhammad?
Because the two names describe two sides of the same prophet. Muhammad stands for God’s majesty and power, as it shone in Moses (as), and Ahmad for God’s beauty and gentleness, as it shone in Jesus (as), and each foretold him by the name that matched his own nature.
In God there are two great groups of attributes. One is His majesty, His power and His strength to establish order and punish wrong. The other is His beauty, His kindness and all that is gentle and wins the heart. Earlier prophets carried both within them, but in each of them one side usually stood out.
Moses (as) was above all a sign of power and firmness. Jesus (as) was above all a sign of love, gentleness and attraction. In the Holy Prophet Muhammad (saw), both sides were united in perfect balance. The name Muhammad expresses the first side, the name Ahmad the second.
That is why it fits that Moses (as) foretold a prophet who would be like himself, pointing to the Muhammad side. Jesus (as), on the other hand, foretold the same prophet by the name that matched his own nature, namely Ahmad. Both spoke of the same prophet, each from his own perspective.
The chapter that directly follows this announcement opens a further door. It first describes how the Holy Prophet Muhammad (saw) appeared among the Arabs. Then it speaks of others who have not yet joined the first believers. When the companions asked about this, he placed his hand on Salman the Persian and spoke of a man from his people who would bring faith back, even if it had gone as far as the stars.
This shows that the message of the Holy Prophet Muhammad (saw) would come to life again in a later age of lost faith through a devoted servant. He would not return himself, but would be represented by this follower. The name Ahmad, with its gentleness and beauty, especially marks this second appearance.