What did the prophet mean with this hadith?

When the child (of Zainab) was brought to Muhammad, dying; its body trembling and moving; the eyes of the Apostle of God shed many tears. And Sad said, "O Messenger of God! What is the weeping and shedding of tears?" Muhammad replied, "This is an expression of the tenderness and compion, which the Lord has put into the hearts of His servants; the Lord does not have compion on and commiserate with His servants, except such as are tender and full of feeling."