It is narrated from Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) in marfu' form (that is, as a saying of the Prophet (peace and blessings be upon him)): "Whoever seeks ruqyah or has himself cauterised has not relied (upon Allah)."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18015