murtayah sambhavanti yah
tasam brahma mahad yonir
aham bija-pradah pita
"It should be understood that all species of life, O son of Kunti, are made possible by birth in this material nature, and that I am the seed-giving father."
Now the Lord says that even the daily creations [nitya srushti] is carried out by Him. Earlier the Lord told that creation of prakruti [prakruta srushti प्रकृति सृष्टि] and occasional creations [naimittika srushti नैमित्तिक सृष्टि] are done by Him. That is fertilizing prakruti with collection of atman and creation of different species were mentioned earlier. Now the Lord mentions about the creation of lord Brahma, lord Shiva, Indra, even you and me and every living being born daily. One might doubt that these creations are done by the respective parents. The Lord clarifies that even these are created by Him only. He is the cause for these daily births of all living beings, also. Kaunteya = son of Kunti [Arjuna]!, sarva-yonisu = in species created by lord Brahma such as Devas, humans, animals, birds, insects, plants, etc., murtaya = bodies, sambhavanti = appear, tasam = they all, brahma = moola prakruti, is the cause. But moola prakruti by itself is not the cause. Moola prakruti by being the body of the Lord is the cause. Aham = I [Sri Krishna] am, pita = father, bija-pradha = fertilizing with seed [into the prakruti]. Just as a male impregnates a female, the Lord impregnates prakruti with the collection of atman. Thus the impregnated prakruti becomes the cause for birth of all living beings. In the case of individual births, the Lord is the antaratma in respective male and female, and becomes the Cause for birth of the young ones. Other than the Lord, no individual is the cause for birth of anyone. Prakruti also, as the body of the Lord, becomes the cause for creation of species. Here some doubts may arise. What is the seed He is fertilizing? It is atma samooham or collection of atman. This is impregnated into prakruti, which is His body, by the Lord as a Father. Thus the Lord is both Nimitta [doer] and upadana [means] cause for the creation. We have to note one difference here. While prakruti is compared to a mother and the Lord to a father, in our life we see father and mother are separate souls and bodies. But here, prakruti is the body of the Lord and He fertilizes it with collection of atman.