Why is sesame seed (til) significant in Pitrudosh rituals?

Sesame seeds (til) hold a unique position in all pitru rituals. The Padma Purana states that sesame originated from the perspiration of Lord Vishnu himself, making them inherently sacred. The Vayu Purana declares that anything offered to ancestors with sesame seeds reaches them as amrit (nectar). Til has the quality of absorbing negative energies and purifying the ritual space. During Tarpan, black sesame seeds mixed with water and barley are offered while reciting the ancestor’s name and gotra — this combination is believed to directly nourish the departed soul.