Śatapatha Brāhmaṇa ("of a hundred paths") 11.5.4.8

11.5.4.8

atha caturviṃśatyahe caturviṃśatirvai saṃvatsarasyārdhamāsāḥ saṃvatsarasammitā vai garbhāḥ prajāyante jāta evāsmiṃstadvācaṃ dadhma iti

Or after twenty-four days, thinking, 'There are twenty-four half-months in the year, and children are born when fashioned for a year: we thus lay speech into this one as soon as he has been born.'