अथ य इच्छेत्पुत्रो मे श्यामो लोहिताक्शो जायेत, त्रीन्वेदाननुब्रुवीत, सर्वमायुरियादिति, उदौदनं पाचयित्वा सर्पिष्मन्तमश्नीयाताम्; ईश्वरौ जनयितवै ॥ १७ ॥
atha ya icchetputro me śyāmo lohitākśo jāyeta, trīnvedānanubruvīta, sarvamāyuriyāditi, udaudanaṃ pācayitvā sarpiṣmantamaśnīyātām; īśvarau janayitavai || 16 ||
16. He who wishes that his son should be born dark with red eyes, study three Vedas and attain a full term of life, should have rice cooked in water, and he and his wife should eat it with clarified butter. Then they would be able to produce such a son.
Simple, natural rice is meant. The mention of water is for precluding other ingredients.