BG 16.20

16.20 असुरीम् demoniacal? योनिम् womb? आपन्नाः entering into? मूढाः deluded? जन्मनि जन्मनि in birth after birth? माम् Me? अप्राप्य not attaining? एव still? कौन्तेय O son of Kunti (Arjuna)? ततः than that? यान्ति (they) fall into? अधमाम् lower? गतिम् condition (path or goal).Commentary These degraded Asuras are cast into the demoniacal wombs. They are reduced to the very lowest condition or the most appalling state. They are cast into utter darkness. They fall into lower and yet lower wombs in response to their own satanic desires and actions and their extreme Tamasic nature. From the birth of a tiger? they will get the birth of a serpent from a serpents they will get the birth of a wormfrom that they will get the birth of a tree? etc. In Sanskrit the suffix Tara denotes comparative degree and Tama is superlative degree. These people get Nikrishtatama Yonis (the lowest wombs).They do not reach Me as their minds are filled with impurities? as they do not tread the path of righteousness in accordance with the injunctions of the scriptures. The diabolical nature is inimical to spiritual progress. Therefore? you will have to annihilate the evil tendencies by cultivating divine alities and the practice of regular meditation. Then and only then will you attain liberation.

— vedicscriptures · exposition · source ↗

It is known that God is all-merciful, but here we find that God is never merciful to the demoniac. It is clearly stated that the demoniac people, life after life, are put into the wombs of similar demons, and, not achieving the mercy of the Supreme Lord, they go down and down, so that at last they achieve bodies like those of cats, dogs and hogs. It is clearly stated that such demons have practically no chance of receiving the mercy of God at any stage of later life. In the Vedas also it is stated that such persons gradually sink to become dogs and hogs. It may be then argued in this connection that God should not be advertised as all-merciful if He is not merciful to such demons. In answer to this question, in the Vedānta-sūtra we find that the Supreme Lord has no hatred for anyone. The placing of the asuras, the demons, in the lowest status of life is simply another feature of His mercy. Sometimes the asuras are killed by the Supreme Lord, but this killing is also good for them, for in Vedic literature we find that anyone who is killed by the Supreme Lord becomes liberated. There are instances in history of many asuras – Rāvaṇa, Kaṁsa, Hiraṇyakaśipu – to whom the Lord appeared in various incarnations just to kill them. Therefore God’s mercy is shown to the asuras if they are fortunate enough to be killed by Him.

— vedicscriptures · exposition · source ↗