Śivaloka–Brahmaloka Varnana
Description of Śivaloka and the Upper Worlds
इत्युक्त्वा शङ्करस्तस्मै ददौ मन्त्रं सुदुर्लभम् / त्रैलोक्यविजयं नाम कवचं परमाद्भुतम्
ityuktvā śaṅkarastasmai dadau mantraṃ sudurlabham / trailokyavijayaṃ nāma kavacaṃ paramādbhutam
So saying, Śaṅkara bestowed upon him a most rare mantra—the wondrous protective armor called “Trailokyavijaya”, the Conquest of the Three Worlds.