first three verses are addressed to vayu alone, next three to indra & vaayu.
indra is psychological interpretations of hymns representing mind power. the word for sense- faculties "indriya" is derived from his name.
his special realm is "swar", a word which means sun or luminous, being akin to surya, the sun. surya represents illumination of ritm (truth) rising upon mind. swar is that plane of mental consciousness which directly receive illumination.
vayu is always associated prana or life energy, which contributes to the system all the ensemble of those nervous activities that in man are support of mental energies governed by indra. their combination constitutes normal mentality of man.
indra and vaayu awaken in consciousness ( cetathah) to the flowing of soma which represents ananda, divine delight of being. this is to say, the mind power and life energy working together in human mentality are to awaken to inflowings of this ananda. ananda thus received constitutes a new action preparing immortal consciousness in mortal & indra and vayu are bidden to come and swiftly perfect these new workings.