SB 10.62.8

tac chrutvā bhagavān kruddhaḥ
 ketus te bhajyate yadā
tvad-darpa-ghnaṁ bhaven mūḍha
 saṁyugaṁ mat-samena te
tat — that; śrutva — hearing; bhagavān — the lord; kruddhaḥ — angry; ketuḥ — flag; te — your; bhajyate — is broken; yadā — when; tvat — your; darpa — pride; ghnam — destroyed; bhavet — will be; mūḍha — O fool; saṁyugam — battle; mat — to me; samena — with Him who is equal; te — your.
Hearing this, Lord Śiva became angry and replied, “Your flag will be broken, fool, when you have done battle with one who is my equal. That fight will vanquish your conceit.”

Lord Śiva could have immediately chastised Bāṇāsura and personally destroyed his pride, but since Bāṇāsura had been such a faithful servant of his, Śiva did not do so.