Relation Between Narsimha And Lord Dattatreya.

According to the 15 chapter of gurucharitra :-

 When The Guru (Jupiter) is in the Sinha (leo) all the rivers have union with Bhagirathi. When guru is in Kanya (Vibro) Bhagirathi comes in Krishna. Have bath in Patal Ganga and see Mallikarjuna. Baths at Kaveri Sangam, Payaswini and Bhavanashini are virtuous. See places like Samudraskanda, Sheshadri, Shri Rangnath, Padmanabh, Shrimat Anant, Trimamalla, Kumbhakonam Kanyakumari, Matsyatirth, Pakshitirth, Rameshwar, Dhanushkoti, Mahalakshmi at Kolhapur, Mahabaleshwar, origin of Krishna. Bahe, Narsinhadeo at Kolegaon Bhuvaneshwari at Bhilawadi, Shrupali, Chhaya Bhagwati (Vishwamitra's place) Shweta Shring, whence Krince flows northwards, Kalyan etc


महाबळेश्वर तीर्थ बरवें |
कृष्णाउगम तेथें पहावें |
जेथें असे नगर "बहें" |
पुण्यक्षेत्र रामेश्वर ||

तयासंनिध असे ठाव |
कोल्ह्ग्रामी नृसिंहदेव |
परमात्मा सदाशिव |
तोची असे प्रत्यक्ष ||
           -गुरुचरित्र अध्याय पंधरावा | ७५-७६ ||

According to the 22 chapter of gurucharitra :-

 Namdharak: "Leaving other holy trees why Shri Guru lived under the Audumbar tree? Greatness of Ashwattha is described even in the Vedas, Why then he preferred Audumbar?"


Siddha: "Shri Vishnu took Narasinhawatar to kill the demon Hranyakashyapu. He tore the belly of the demon by his nails, took out the intestines and put them around his neck as a wreath. Narsimha's nails were filled with strong poison and so caused great heat in his body. Shri Lakshmi took Audumbar fruits and thrush Narsimha's nails in them. The poison and the heat of the body subsided and Lakshmi and Narasimha were pleased. So they blessed the Audumbar tree, `You shall always bear fruits and people will worship you as the Kalpataru. Strong poisons will be subsided even by your sight and sterile women will get issues if they worship you with devotion.'


Audumbar is a Kalpataru in Kaliyug, hence Shri Guru lived under it Brahma, Vishnu and Mahesh live here in the form of Shri Dattatreya.

 ऐसा वृक्ष औदुंबरु |
कलियुगीं तोचि कल्पतरू |
नरसिंहमूर्ति होता उग्रु |
शांत झाली तयापाशीं ||



याकारणे श्रीगुरूमूर्ति |
नृसिंहमंत्र उपासना करिती |
उग्रत्वाची करावया शांती |
औदुंबरी वास असे ||
 अवतार आपण तयाचे (नृसिंह देवाचे) |
स्थान आपुलें असे साचें |
शांतवन करावया उग्रत्वाचें |
म्हणोनी वास औदुंबरीं ||
            -गुरुचरित्र अध्याय एकोणिसावा २६, २७, २८ ||