Etymology and English translation based on Anvaya (logical connection of words) of Maharshi Dayanad Saraswati (M.D.S)- -

He=O! (sabhᾱdhyakșha)=chairperson, (manuṣyā) human being, (yathā)=as, (kṛṣīvalāḥ)=cultivating farmers, (krivim)=digging a well, (samprāpya)=obtaining water properly, (tajjalena)=with its water, (kṣetrāṇi)=the fields, (siñcanti)=irrigate, (yathā)=and, [jaise]=as, (vājayantam)=air driving water, (indubhiḥ)=with waters, (śatakratum)=through which many actions take place, (maṃhiṣṭham)=such very great, (indram)=means of attaining God, (ca) =are as well, (tathā)=in the same way, (tvam)=you, (api)=also,(prajāḥ)= of children, (sukhaiḥ)=for the happiness, (siñca)=irrigating with water, (saṃyojaya)=anoint.

English Translation (K.K.V.) -

O chairperson human being! As the cultivating farmers dug wells and get well water and irrigate the fields with that water and like the air that moves the water, the waters which have many actions. There are also means to attain such extremely great opulence, in the same way, for the happiness of children, anoint them by irrigating them with water i.e. bathing them.

TranslaTranslation of gist of the mantra by Maharshi Dayanandtion of gist of the mantra by Maharshi Dayanand -

There is simile as a figurative in this mantra. Just as human beings are happy by first digging a well, bathing with that water and irrigating the gardens of the field, etc., in the same way, learned people are happy by doing many tasks by using fire in the instruments properly, establishing water in relation to it and running them.