"I heard Sharid say: 'I herd the Messenger of Allah say: Whoever kills a small bird for no reason, it will beseech Allah on the Day of Resurrection saying: O Lord, so and so killed me for no reason. And he did not kill me for any beneficial purpose."' (Using translation from Nasāʾī 4446)
سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ مَنْ قَتَلَ عُصْفُورًا عَبَثًا عَجَّ إِلَى اللهِ ﷻ يَوْمَ الْقِيَامَةِ مِنْهُ يَقُولُ يَا رَبِّ إِنَّ فُلَانًا قَتَلَنِي عَبَثًا وَلَمْ يَقْتُلْنِي لِمَنْفَعَةٍ