Musannaf Ibn Abi Shaybah 23745 — People who pass by camels

Sayyiduna Umar (may Allah be pleased with him) said: When you pass by someone's camels, call out to the herdsman three times, 'O herdsman.' If he answers your call and comes, ask him for milk. If he does not answer your call, then milk them yourselves, use the milk, and tie up their udders again.