The Tibetan form of Buddhism is rich in rituals. They include the reading of texts but also, together with this, the symbolic wielding of ritual artefacts. Some of the artefacts that are held in the hands in the ritual are well known - a bell, ghanta, in one and a thunderbolt, vajra in the other. Besides them, there's also the ritual dagger, phurba, amongst others.
The daggers role is associated with expulsion or holding fast of demons and other creatures of the mind. When it is driven into the ground, the floor, or a bowl of rice, it stabilizes the location before a ritual. The phurba seen here is from Mongolia where it can sometimes be seen in unusual sizes. In this case, it has stood next to the altar in a temple.
Early in his career, Sven Hedin came into contact with the northern, Tibetan Buddhism, with which he obviously sympathised. During his last large expedition of 1927-35, he had several colleagues who were able to devote themselves to studying and documenting Buddhism's material culture. A shared project was to obtain two or three copies of the temple, fully furnish them, and display them for a Western audience.