Śatapatha Brāhmaṇa ("of a hundred paths") 10.2.6.11

10.2.6.11

sa u vā iṣṭakaikaśatavidhaḥ yāḥ pañcāśatprathamā iṣṭakā yāścottamāstāḥ śataṃ vidhā atha yā etadantareṇeṣṭakā upadhīyante saivaikaśatatamī vidhā

And, indeed, it is a hundred and one-fold in respect of bricks,--the first fifty bricks and the last fifty which are (laid down) make a hundred forms (parts); and the bricks which are laid down between (those two sets) are the one hundred and first form.