Shatapatha Brahmana 5.1.5.13

5.1.5.13

tadyadrājanyaḥ pravidhyati | eṣa vai prajāpateḥ pratyakṣatamāṃ yadrājanyastasmādekaḥ sanbahūnāmīṣṭe yadveva caturakṣaraḥ prajāpatiścaturakṣaro rājanyastasmādrājanyaḥ pravidhyati saptadaśa pravyādhānpravidhyati saptadaśo vai prajāpatistatprajāpatimujjayati

A Râganya then shoots seventeen arrow's ranges northwards from the edge of the altar; for as much as is one arrow's range, so much is Pragâpati crosswise; and as much as are seventeen arrow's ranges, so much is Pragâpati lengthwise.