Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever shows mercy, even if it is in the matter of slaughtering a bird, Allah Almighty will show mercy to him on the Day of Resurrection."

Sayyiduna Muawiyah bin Qurrah narrates from his father that a man said: O Messenger of Allah! I slaughter a goat and show kindness to it (how is this act?). The Prophet (ﷺ) said: "If you have shown kindness to the goat, then Allah, the Exalted, will have mercy on you."