Rig Veda III.4.2, dedicated to Āprīs, says as follows:
यं देवासस्त्रिरहन्नायजन्ते दिवे-दिवे वरुणो मित्रो अग्निः | सेमं यज्ञं मधुमन्तं कर्धी नस्तनूनपाद घर्तयोनिं विधन्तम ||
yaṃ devāsastrirahannāyajante dive-dive varuṇo mitro aghniḥ | semaṃ yajñaṃ madhumantaṃ kṛdhī nastanūnapād ghṛtayoniṃ vidhantam ||
Tanūnapāt whom the deities - MITRA, VARUNA and AGNI, worship daily thrice a day, render this our sacred rain-engendering sacrifice productive of water.
The translation is of H.H. Wilson.
tanun indicates the wind or vAyu
napāt indicates grand son or descendant
So it might indicate grandson or descendant of vAyu.
My questions are:
Who is the Tanūnapāt whom the deities - MITRA, VARUNA and AGNI, worship daily thrice a day?
Was worship of 3 times mentioned in this mantra, a precursor to performing of Sandhyavandana 3 times a day?