Each mantra in Devanāgarī and IAST, with a plain English rendering first and the interpretation kept one tap away.
Śiva Gāyatrī
ॐ तत्पुरुषाय विद्महे
महादेवाय धीमहि
तन्नो रुद्रः प्रचोदयात् ॥
oṃ tatpuruṣāya vidmahe
mahādevāya dhīmahi
tanno rudraḥ pracodayāt ||
We contemplate the Supreme Person; we meditate upon the Great God. May Rudra impel us onward.
tatpuruṣa is the fourth of Śiva’s five faces, turned east and associated with the unmanifest. pracodayāt — “may he urge forward” — is the same optative that closes the Sāvitrī gāyatrī.
Rudra Gāyatrī
ॐ पुरुषस्य विद्महे
सहस्राक्षाय महादेवाय धीमहि
तन्नो रुद्रः प्रचोदयात् ॥
oṃ puruṣasya vidmahe
sahasrākṣāya mahādevāya dhīmahi
tanno rudraḥ pracodayāt ||
We know the Puruṣa; we meditate on the thousand-eyed Great God. May Rudra impel us onward.
sahasrākṣa, “thousand-eyed,” is more often an epithet of Indra; its transfer to Rudra marks the Purāṇic absorption of Vedic sovereignty into Śiva.
Mahādeva Gāyatrī
ॐ महादेवाय विद्महे
रुद्रमूर्तये धीमहि
तन्नः शिवः प्रचोदयात् ॥
oṃ mahādevāya vidmahe
rudramūrtaye dhīmahi
tannaḥ śivaḥ pracodayāt ||
We contemplate the Great God; we meditate upon the form of Rudra. May Śiva impel us onward.