In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Allaah [The Most High] said:
وَيَدْعُ الْإِنسَانُ بِالشَّرِّ دُعَاءَهُ بِالْخَيْرِ ۖ وَكَانَ الْإِنسَانُ عَجُولًا
And man invokes [Allaah] for evil as he invokes [Allah] for good and man is ever hasty. [17:11]
This [behaviour] is from the ignorance and hastiness of the human being when he supplicates for evil against himself, his children and his wealth at the time of anger. He hastens to make such an evil supplication just as he hastens to supplicate for something good. But Allaah-out of His kindness-responds to him when he asks for good and not when he asks for evil. Allaah [The Most High] said:
وَلَوْ يُعَجِّلُ اللَّهُ لِلنَّاسِ الشَّرَّ اسْتِعْجَالَهُم بِالْخَيْرِ لَقُضِيَ إِلَيْهِمْ أَجَلُهُمْ
And were Allah to hasten for mankind the evil [they invoke for themselves and for their children, etc. while in a state of anger] as He hastens for them the good (they invoke) then they would have been ruined. [10:11]
[Source: An Excerpt from ‘Tayseer Al-Kareem Ar-Rahmaan Fee Tafseer Kalaam Al-Mannaan.’ Slightly paraphrased]