Lord Narsimha is one of the prominent Vishnu's incarnation. Vishnu is believed to have taken Narsimha avatar to destroy the demon king Hiranyakashipu, as described in Shrimad Bhagwat
Also, in the Wikipedia it is mentioned that after killing Hiraṇyakaśipu, none of the present demigods are able to calm Narasiṁha's wrath. After Hiraṇyakaśipu was killed, the Lord continued to be very angry, and the demigods, could not pacify Him.
So in order to pacify Lord Narsimha, all the gods and goddesses call his consort, Lakshmi, who assumes the form of Pratyangira and pacifies the Lord.
My Question is : Which scripture describe Lakshmi assuming form of Pratyangira, also called as Narasimhi, to pacify Vishnu?
Side Note: As per Shrimad Bhagvat, it is Prahlāda who came forward and pacified the Lord’s anger, and not Lakshmi.