The Langar system originated during Guru Nanak Dev Ji's time. Once as a child, he was sent to the city by his father - Bhai Kalu Chand - to perform a profitable trade; he was given money for this purpose and a friend known as Bhai Bala was sent with him. During the journey however, the Guru came across some Sadhus (holy ascetics) who were resting in a nearby forest, the Guru spent most of the evening with them before continuing on his journey. Once at the city, he spent the money given by his father on food for the Sadhus - much to the discouragement of his friend. When the Guru returned home, his father scolded him.

Throughout his travels, he caused for food to be distributed wherever he rested and some years later, when he returned from his journeys, the prophet caused for the institution of Langar to become regular at the village of Kartarpur. The langar system continued uninterrupted from that time. During Guru Amar Das Ji's time, the Guru made it compulsory that anybody wishing to see him must first partake in the langar Pahile Pangat Pishe Sangat. The emperor Akbar was not exempt from this rule and during his visit, he found himself sitting alongside the lowly folks of his empire eating the same food as them.

The Langar is prepared from the food donations that are made before the Guru Granth Sahib, a kitchen is set aside for this purpose. When the food is prepared, it is taken before the Guru Granth Sahib and an Ardas (prayer) is performed asking the Guru to accept the food and bless the sevadars who prepared it and bless those that eat from the Langar. Following this, it is served in the Langar hall. Traditionally, the head must be covered and shoes removed in this room, the langar should be served on the floor with the sangat sitting cross legged. It is advisable not to leave leftovers. Meat - including fish and eggs and alcoholic/narcotic substances are strictly against the Sikh diet, hence these are not allowed on Gurudwara premises.