Al Dai al Ajal Syedna Mufaddal Saifuddin TUS described the importance of rayhãn (fragrance) in today’s waaz mubarak.
Botanical Source and Characteristics

'Myrtus Communis' is an evergreen shrub which has a glossy aromatic foliage and white flowers followed by purple-black oval berries.

Myrtus communis is a part of the Myrtacea plant family (the myrtle family). The family also includes several aromatic plants (clove, allspice) and many characteristic Australian plants (such as eucalyptus tree and bottlebrushes)

The evergreen common myrtle has glossy dark opposite leaves, that are a little paler below, and pointed at both ends; virtually stalk less, and about an inch long. Held to the light, the leaves show many small translucent dots containing oil whose fragrance is released by crushing.

Leaves of the myrtle family are often characterized by fragrance. The modest white flower have lots of long, yellow, tipped stamens, while the elongated berries are blue-black, terminated in some remnants of flower and containing many white kidney shaped seeds.

Where are they found?

It is native to southern Europe, North Africa, western Asia, and the Indian Subcontinent

Myrtus communis (Myrtaceae) is one of the drugs popularly used in the Unani system of phyto medicine since the ancient Greek period. From time immemorial, different parts of this plant and essential oil have been used for a variety of purposes such as cosmetics (hair fall control), flavoring of food and drinks as well as extensive therapeutic purposes.

Rayhãni script takes its name from the basil plant which is also known as rayhãn.
The word rayhãn appears in the Quran in two suras, al-Rahman and al-Waq'ia.

Al Dai al Ajal Syedna Mohammed Burhanuddin RA states:

Benefits of Myrtus communis:

Myrtle essential oil and extracts have antibacterial, antifungal, and antioxidant properties.

Myrtle can be used in food preservation

Ethno botanical information revealed that Myrtus communis (L) has been a folkloric repute for the treatment of several diseases like gastric ulcer, diarrhea, dysentery, cancer, rheumatism, haemorrhage, deep sinuses, leucorrhoea, haemorrhoid, inflammation, dyspepsia, anxiety, insomnia, diabetes, hypertension, pulmonary disorders, and skin diseases

Moreover, ethno pharmacological studies revealed that the plant is endowed with extensive pharmacological activities, including antimicrobial, anti diarrheal, anti diabetic, antispasmodic, vasodilator, antiulcer, antioxidant, anticancer, anxiolytic, sedative-hypnotic, and anti-inflammatory activities, among others.

Ancient doctors believed that among its medical benefits is that if its fumes were inhaled, they would clear the brain of rotten moisture and impurities, and if it's water were drunk, it would remove jaundice and blood retention wherever it occurred, and if it's powder were applied on a wound, it would help it heal.

Ibn Sina said: It is useful for haemorrhoids, vertigo, and nosebleed.

The specialty of this flower is that it is an antioxidant, and also treats deep sinus problems. This knowledge helps us better understand the kalemaat of al Dai al Ajal Syedna Mufaddal Saifuddin TUS.

Al Dai al Ajal Syedna Mufaddal Saifuddin while praying shahadat of Rasulullah SAW stated:

This bayan mubarak inspires and compels Mumineen to do Buka and Matam upon Imam Husain AS during their lifetimes, so that one day, on their deathbeds, it will act as the Rayhan that eases the transcending of the Nafs.