Sandipani
Sandīpanī Muni was the guru of Bhagavan Śrī Kṛṣṇa. Sandīpanī was a ṛṣi/muni/saint of Ujjain.
Sandīpanī means, "Possessor (ī) of complete (sam-) illuminating (-dīpana-)." The Saṅgīta-Sāra-Saṅgraha relates the name as a particular musical śruti (text).
The Sandīpanī Muni āśrama is located 2 km outside Ujjain, in the Indian state of Madhya Pradesh. The area near the āśrama, known as Aṅkapāta, is popularly believed to have been the place used by Bhagavan Śrī Kṛṣṇa for washing his writing tablets. A locally-sourced narrative relates that the numerals 1 to 100 found inscribed on a stone were originally engraved by Saṁdīpanī.
Near the āśrama is the Gomti Kund, a stepped water tank. Legend has it that this is where Kṛṣṇa summoned all the holy waters from various centres so that his elderly Guru, Saṁdīpanī Muni would not have to travel other holy places.