The Prophet ﷺ said: If anyone kills a gecko with the first blow, such and such number of good deeds will be recorded for him, if he kills it with the second blow, such and such number of good deeds will be recorded for him less than the former; and if he kills it with the third blow, such and such number of good deeds will be recorded for him, less than the former. (Using translation from Abū Dāʾūd 5263)
قَالَ رَسُولُ اللهِ ﷺ مَنْ قَتَلَ وَزَغَةً فِي أَوَّلِ ضَرْبَةٍ فَلَهُ كَذَا وَكَذَا حَسَنَةً وَمَنْ قَتَلَهَا فِي الضَّرْبَةِ الثَّانِيَةِ فَلَهُ كَذَا وَكَذَا حَسَنَةً أَدْنَى مِنَ الْأُولَى وَمَنْ قَتَلَهَا فِي الضَّرْبَةِ الثَّالِثَةِ فَلَهُ كَذَا وَكَذَا حَسَنَةً أَدْنَى مِنَ الثَّانِيَةِ وَفِي حَدِيثِ خَالِدٍ دُونَ الْأُولَى وَقَالَ لِدُونِ الثَّانِيَةِ وَالْبَاقِي سَوَاءٌ