Meaning
Arjuna spoke
Such progeny (varna-samkara) send those who have destroyed their clan in war and all others of the clan to hell. They also cause the fall of the spirits of ancestors, as they cease to receive their ceremonial offerings of water and food. (1:42)
Sanskrit
अर्जुन उवाच
सङ्करो नरकायैव कुलघ्नानां कुलस्य च ।
पतन्ति पितरो ह्येषां लुप्तपिण्डोदकक्रियाः॥
Word-by-word
सङ्करः नरकाय एव कुल-घ्नानाम् कुलस्य च
पतन्ति पितरः हि एषाम् लुप्त-पिण्ड-उदक-क्रियाः।
Commentary
Shraddha and Tarpana are Vedic rites wherein the departed ancestors are offered foodstuff and water by their progeny on specified occasions according to prescribed procedures. It is believed that the souls of the ancestors, wherever they may be, receive the essence of these offerings, drawing strength and satisfaction from them. The ancestors of individuals born of parents from different Varnas or castes are believed to be unable to receive the offerings of food and water. Without this nourishment, they are thought to fall from their higher realms.
According to the priestly class, ancestors fail to receive Pinda (food) and water due to the lack of respect from individuals born of parents from different Varnas, known as Varna-samkara. This lack of reverence results in a neglect of performing Shraddha-Tarpana rituals for the ancestors. Even if these rituals are performed by Varna-samkara individuals, the ancestors do not receive the offerings because they lack the rightful essence. This is because the orthodox Hindu scriptures do not grant Varna-samkara individuals the right to perform such sacred deeds, according to the orthodox belief system.
There is no endorsement of these views in the Gitā.