Fa inna lillaahi saa'aatan laa yuraddo fihin ne saa'ilan"
"For verily Allah has certain times wherein no person who asks is rejected
This hadith has been quoted in many ways.
In Mishkat it is reported by Hazrat Jabir Radhiallahu Anhu: "Do not curse yourselves and do not curse your possessions or your children. Let it not be such, that your dua is made at such a time when Allah accepts your dua.
This disease is very prevalent amongst women when they are angered by their children displeasing them, they curse them: "Mar Jaa" (Go and perish) or "Go and become made!" When this curse is accepted and becomes a reality they sit and cry.
In my classes I have always stressed that when you make dua, then make those duas which are from the texts of Quran and Hadith, because there is nothing regarding one's needs in this world and the hereafter left out. As well as how to ask for it. I would like to write down a little story which is bit off the point but is quite illustrative. I have heard it on more than one occasion from the Elders and have told it in class quite often, that one should not make dua in your words. Rather make dua in the words of the word of the "Beloved of Allah" and such words have greater value in the sight of Allah. Secondly these words (found in the Ahaadith) are so comprehensive that whatever one wishes to ask for, is included there in.