It is narrated from Sayyiduna Samurah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever conceals one who has stolen from the spoils of war is like him, and whoever gathers with a polytheist and lives with him is like him."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6994