Hadith.1879 - Imam Jafar ibn Muhammad Al-Sadiq (as) was asked about a person in a state of Ihram smelling basil. Imam (as) said: "No."
Imam (as) was asked about a fasting person. Imam (as) said: "No."
Imam (as) was asked if a fasting person may smell perfume or incense. Imam (as) said: "Yes."
Imam (as) was asked: "How is it permissible for him to smell perfume but not basil?"
Imam (as) replied: "Because perfume is a Sunnah, while basil is an innovation for the fasting person."