Majma al-Zawaid — Hadith 18114

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) reports this saying of the Prophet (peace and blessings be upon him): "The lawful is clear and the unlawful is clear, and between them are some doubtful matters. Whoever falls into them is likely to become a sinner, and whoever avoids them does better for his religion, like one who grazes beside a protected pasture who may well enter the pasture. Every king has his own protected pasture, and the protected pasture of Allah Almighty is the things He has made unlawful."
Al-Tabarani recorded it; its chain contains a narrator, Sabiq al-Jazari, whom I do not know; the remaining narrators are thiqat (trustworthy).