Sayyiduna Abu Sirmah (may Allah be pleased with him) narrates from the Messenger of Allah (peace and blessings be upon him) that he (peace and blessings be upon him) said: "Whoever harms (another), Allah will harm him; and whoever causes hardship (to another), Allah will cause hardship for him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20445