Musannaf Ibn Abi Shayba 13:2386

Abu Bakr narrated to us, he said: Yazid narrated to us, he said: Ibn Abi Za’idah narrated to us, from Abu Ya’qub al-Thaqafi, from Khalid ibn Abi Malik, he said: I sold a commodity to Muhammad ibn Sa’id. He said: "Give me your hand so that I may shake hands with you, for the Messenger of Allah, may Allah bless him and grant him peace, said: 'Blessing is in the handshaking.'"