Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 30: Rāma and Lakṣmaṇa Protect Viśvāmitra’s Sacrifice
Text 1.30.8

रामस्यैवं ब्रुवाणस्य त्वरितस्य युयुत्सया।
प्रजज्वाल ततो वेदिः सोपाध्यायपुरोहिता॥

rāmasyaivaṁ bruvāṇasya tvaritasya yuyutsayā
prajajvāla
tato vediḥ sopādhyāya-purohitā

rāmasya = Śrī Rāma; evam bruvāṇasya = while He was speaking thus; tvaritasya = was eager; yuyutsayā = to enter into war [with the rākṣasas]; prajajvāla tataḥ = blazed; vediḥ = the sacrificial altar; sa-upādhyāya-purohitā = with Viśvāmitra and the sacrificial priests.

Śrī Rāma was eager to enter into war [with the rākṣasas]. While He was speaking thus, the sacrificial altar with Viśvāmitra and the sacrificial priests blazed.

This was an omen signifying the arrival of the rākṣasas.