Musnad Abu Ya'la al-Mawsili 159:6

Abu Bakr narrated to us, Abu Abd al-Rahman al-Muqri narrated to us, from Sa'id ibn Abi Ayyub, Ubayd Allah ibn Abi Ja'far narrated to us, from Abd al-Rahman al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever is offered sweet-smelling herbs (rayhan), let him not refuse them, for they are light to carry and pleasant in scent."