महामुनौ when the mighty ascestic, तस्मिन् विश्वामित्रे that Visvamitra, सन्तप्यमाने while peforming penance, सुराणाम् for devatas, वासवस्य च for Indra also, सुमहान् greatly, संभ्रम: आसीत् perturbance over took.
When the mighty asetic Viswamitra was peforming penance, the gods as well as Indra got deeply perturbed.