SB 7.9.14

tad yaccha manyum asuraś ca hatas tvayādya
 modeta sādhur api vṛścika-sarpa-hatyā
lokāś ca nirvṛtim itāḥ pratiyanti sarve
 rūpaṁ nṛsiṁha vibhayāya janāḥ smaranti
Synonyms: 
tat — therefore; yaccha — kindly give up; manyum — Your anger; asuraḥ — my father, Hiraṇyakaśipu, the great demon; ca — also; hataḥ — killed; tvayā — by You; adya — today; modeta — take pleasure; sādhuḥ api — even a saintly person; vṛścika-sarpa-hatyā — by killing a snake or a scorpion; lokāḥ — all the planets; ca — indeed; nirvṛtim — pleasure; itāḥ — have achieved; pratiyanti — are waiting (for pacification of Your anger); sarve — all of them; rūpam — this form; nṛsiṁha — O Lord Nṛsiṁhadeva; vibhayāya — for mitigating their fear; janāḥ — all the people of the universe; smaranti — will remember.
Translation: 
My Lord Nṛsiṁhadeva, please, therefore, cease Your anger now that my father, the great demon Hiraṇyakaśipu, has been killed. Since even saintly persons take pleasure in the killing of a scorpion or a snake, all the worlds have achieved great satisfaction because of the death of this demon. Now they are confident of their happiness, and they will always remember Your auspicious incarnation in order to be free from fear.
Purport: 

The most important point in this verse is that although saintly persons never desire the killing of any living entity, they take pleasure in the killing of envious living entities like snakes and scorpions. Hiraṇyakaśipu was killed because he was worse than a snake or a scorpion, and therefore everyone was happy. Now there was no need for the Lord to be angry. The devotees can always remember the form of Nṛsiṁhadeva when they are in danger, and therefore the appearance of Nṛsiṁhadeva was not at all inauspicious. The Lord’s appearance is always worshipable and auspicious for all sane persons and devotees.