Manava Dharmashastra 4.83

4.83

keśagrahān prahārāṃś ca śirasy etān vivarjayet
śiraḥsnātaś ca tailena nāṅgaṃ kiṃ cid api spṛśet //

Let him avoid (in anger) to lay hold of (his own or other men's) hair, or to strike (himself or others) on the head. When he has bathed (submerging) his head, he shall not touch any of his limbs with oil.