After marrying Devakī, Vasudeva was returning home with her on a chariot driven by Kaṁsa, her brother, when an ominous voice addressed Kaṁsa, warning him that Devakī's eighth son would kill him. Upon hearing this omen, Kaṁsa was immediately ready to kill Devakī, but Vasudeva diplomatically began to instruct him. Vasudeva stressed that it would not be good for Kaṁsa to kill his younger sister, especially at the time of her marriage. Anyone who possesses a material body must die, Vasudeva advised him. Every living entity lives in a body for some time and then transmigrates to another body, but one is unfortunately misled into accepting the body as the soul. If a person under this mistaken conception wants to kill another body, he is condemned as hellish.
(Srimad Bhagavatam-----10:1----summary).

Thus Vasudeva used both sāma and bheda to pacify Kaṁsa. Praising Kaṁsa's qualifications was glorification, and praising him as a descendant of the bhoja-vaṁśa appealed to sambandha, relationship. Speaking of "your sister" was an appeal to identity. Speaking about killing a woman raises questions about fame and welfare, and arousing fear of the sinful act of killing one's sister during her marriage ceremony is an aspect of bheda. The Bhoja dynasty refers to those who were simply interested in sense gratification and were therefore not very aristocratic. Another meaning of bhoja is "fighting." These were indications of defamation for Kaṁsa. When Vasudeva addressed Kaṁsa as dīna-vatsala, this was excessive praise. Kaṁsa would accept calves as a form of revenue from his poor constituents, and therefore he was called dīna-vatsala. Vasudeva knew very well that he could not by force rescue Devakī from the imminent danger. Devakī was actually the daughter of Kaṁsa's uncle, and therefore she is described as suhṛt, meaning "relative." It is stated that Kaṁsa refrained from killing his close relation Devakī because if he had killed her, a great fight would have ensued among the other members of the family. Kaṁsa refrained from provoking this great danger of a family fight, for it would have caused many persons to lose their lives.
(Srimad Bhagavatam-----10:1----summary).

The system of giving a dowry to one's daughter has existed in Vedic civilization for a very long time. Even today, following the same system, a father who has money will give his daughter an opulent dowry. A daughter would never inherit the property of her father, and therefore an affectionate father, during the marriage of his daughter, would give her as much as possible. A dowry, therefore, is never illegal according to the Vedic system. Here, of course, the gift offered as a dowry by Devaka to Devakī was not ordinary. Because Devaka was a king, he gave a dowry quite suitable to his royal position. Even an ordinary man, especially a high-class brāhmaṇa, kṣatriya or vaiśya, is supposed to give his daughter a liberal dowry. Immediately after the marriage, the daughter goes to her husband's house, and it is also a custom for the brother of the bride to accompany his sister and brother-in-law to exhibit affection for her. This system was followed by Kaṁsa. These are all old customs in the society of varṇāśrama-dharma, which is now wrongly designated as Hindu. These long-standing customs are nicely described here.
(Srimad Bhagavatam-----10:1:31:32-----purport).

According to Vedic principles, a brāhmaṇa, an old man, a woman, a child or a cow cannot be killed under any circumstances. Vasudeva stressed that Devakī was not only a woman but a member of Kaṁsa s family. Because she was now married to Vasudeva, she was para-strī, another man's wife, and if such a woman were killed, not only would Kaṁsa be implicated in sinful activities, but his reputation as king of the Bhoja dynasty would be damaged. Thus Vasudeva tried in many ways to convince Kaṁsa in order to stop him from killing Devakī.
(Srimad Bhagavatam-----10:1:37-----purport).

Kaṁsa has here been described as asabhya, meaning "uncivilized" or "most heinous," because he killed the many children of his sister. When he heard the prophecy that he would be killed by her eighth son, this uncivilized man, Kaṁsa, was immediately ready to kill his innocent sister on the occasion of her marriage. An uncivilized man can do anything for the satisfaction of his senses. He can kill children, he can kill cows, he can kill brāhmaṇas, he can kill old men; he has no mercy for anyone. According to the Vedic civilization, cows, women, children, old men and brāhmaṇas should be excused if they are at fault. But asuras, uncivilized men, do not care about that. At the present moment, the killing of cows and the killing of children is going on unrestrictedly, and therefore this civilization is not at all human, and those who are conducting this condemned civilization are uncivilized asuras.
(Srimad Bhagavatam-----10:3:22-----purport).

Vasudeva and Nanda Mahārāja were so intimately connected that they lived like brothers. Furthermore, it is learned from the notes of Śrīpāda Madhvācārya that Vasudeva and Nanda Mahārāja were stepbrothers. Vasudeva's father, Śūrasena, married a vaiśya girl, and from her Nanda Mahārāja was born. Later, Nanda Mahārāja himself married a vaiśya girl, Yaśodā. Therefore his family is celebrated as a vaiśya family, and Kṛṣṇa, identifying Himself as their son, took charge of vaiśya activities (kṛṣi-go-rakṣya-vāṇijyam (B.G.18:44). Balarāma represents plowing the land for agriculture and therefore always carries in His hand a plow, whereas Kṛṣṇa tends cows and therefore carries a flute in His hand. Thus the two brothers represent kṛṣi-rakṣya and go-rakṣya.
(Srimad Bhagavatam-----10:5:20-----purport).

Gargamuni did disclose to Nanda Mahārāja that Balarāma would be known as Saṅkarṣaṇa because of uniting two families—the yadu-vaṁśa and the vaṁśa of Nanda Mahārāja—one of which was known as kṣatriya and the other as vaiśya. Both families had the same original forefather, the only difference being that Nanda Mahārāja was born of a vaiśya wife whereas Vasudeva was born of a kṣatriya wife. Later, Nanda Mahārāja married a vaiśya wife, and Vasudeva married a kṣatriya wife. So although the families of Nanda Mahārāja and Vasudeva both came from the same father, they were divided as kṣatriya and vaiśya. Now Baladeva united them, and therefore He was known as Saṅkarṣaṇa.
(Srimad Bhagavatam-----10:8:12-----purport).