Forbidden in the scriptures
SB Canto 1
In all circumstances killing of innocent living beings is forbidden in the scriptures.
SB 1.8.49, Purport: Whenever there is a war, there is certainly a massacre of many innocent living beings, such as boys, brāhmaṇas and women, whose killing is considered to be the greatest of sins. They are all innocent creatures, and in all circumstances killing of them is forbidden in the scriptures. Mahārāja Yudhiṣṭhira was aware of these mass killings. Similarly, there were friends, parents and preceptors also on both sides, and all of them were killed. It was simply horrible for him to think of such killing, and therefore he was thinking of residing in hell for millions and billions of years.
Beef is forbidden in the scriptures, and the bulls and cows are offered special protection by followers of the Vedas.
SB 1.16.20, Purport: The meat-eaters are generally called mlecchas. But all meat-eaters are not mlecchas. Those who accept meat in terms of scriptural injunctions are not mlecchas, but those who accept meat without restriction are called mlecchas. Beef is forbidden in the scriptures, and the bulls and cows are offered special protection by followers of the Vedas. But in this age of Kali, people will exploit the body of the bull and the cow as they like, and thus they will invite sufferings of various types.
A devotee must have only one initiating spiritual master because in the scriptures acceptance of more than one is always forbidden.
CC Adi 1.35, Purport: If one develops love for Kṛṣṇa by Kṛṣṇa conscious activities, one can know the Supreme Absolute Truth, but he who tries to understand God simply by logical arguments will not succeed, nor will he get a taste for unalloyed devotion. The secret is that one must submissively listen to those who know perfectly the science of God, and one must begin the mode of service regulated by the preceptor. A devotee already attracted by the name, form, qualities, etc., of the Supreme Lord may be directed to his specific manner of devotional service; he need not waste time in approaching the Lord through logic. The expert spiritual master knows well how to engage his disciple’s energy in the transcendental loving service of the Lord, and thus he engages a devotee in a specific devotional service according to his special tendency. A devotee must have only one initiating spiritual master because in the scriptures acceptance of more than one is always forbidden. There is no limit, however, to the number of instructing spiritual masters one may accept. Generally a spiritual master who constantly instructs a disciple in spiritual science becomes his initiating spiritual master later on.