As the legend goes, thirty bhikkhus were journeying with the intention of spending Vassa with Gautama Buddha.[1] However, Vassa began before they reached their destination and they had to stop.[1][4] According to Buddha's guidelines for Vassa, mendicant monks shouldn't travel during the rainy season as they may unintentionally harm crops and/or insects during their journey.[5] As such, the monks had to stop.[1][4]
Afterwards, the Buddha rewarded the monks by demonstrating a way to practice sharing and generosity. A lay disciple had previously donated cloth to the Buddha, so the Buddha now gave that cloth to the group of monks and told them to make it into a robe and then offer it as a gift to one of them. A frame, called a Kathina, was used to spread the robe while it was being made