Lord Buddha's image is sometimes shown with the hand gesture called 'Bhumisparsha Mudra'. It symbolizes

1. Buddha's reminder to his followers that they all arise from the Earth and finally dissolve into the Earth, and thus this life is transitory
2. Buddha's calling of the Earth to watch over Mara and to prevent Mara from disturbing his meditation
3. Buddha's calling of the Earth to witness his purity and chastity despite the temptations of Mara
4. All of these