"Man is created of haste." The interpretation of Mujahid is: he is created hasty.
Allah said: "I will show you My signs, so do not ask Me to hasten them." This was because they used to ask the Prophet—peace be upon him—to hasten the punishment, out of mockery and denial.
﴿خلق الْإِنْسَان من عجل﴾ تَفْسِيرُ مُجَاهِدٍ: خُلِقَ عَجُولًا.
قَالَ اللَّهُ: ﴿سَأُرِيكُمْ آيَاتِي فَلا تَسْتَعْجِلُونِ﴾ وَذَلِكَ لِمَا كَانُوا يَسْتَعْجِلُونَ بِهِ النَّبِي عليه السلام مِنَ الْعَذَابِ اسْتِهْزَاءً مِنْهُمْ وَتَكْذِيبًا.