Sayyiduna al-Ash'ath bin Qays (may Allah be pleased with him) came to the Prophet (peace and blessings be upon him) with the delegation of Kindah, and the Prophet (peace and blessings be upon him) said to him: "Do you have any children?" He said: No, except for a child who was born to me when I set out to come to you, and I wish that in his place the people had food to eat their fill. The Prophet (peace and blessings be upon him) said: "Do not say that, for in them (children) there is coolness of the eyes, and reward when they pass away. And if you have said that, (it is also true that) they are a cause of cowardice, grief and miserliness."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 642