Jaiminīya (Talavakāra) Brāhmaṇa 1.18.p5

1.18.p5

tadvā idaṃ manaḥ pūrvaṃ yatpaścā vāganveti tasmādvatsaṃ pūrvaṃ yantaṃ paścā mātānveti

For the mind goes first, and speech follows behind; therefore, as the calf goes first, the mother follows behind.