Prabhupāda: I am accepting disciples so I am taking responsibility of the sinful reactions. So similarly a king levying taxes, that means that he will take the share, the sinful or pious life of the citizens. Therefore if he keeps the citizens pious life, then he will be profited and citizens will be profited. Otherwise he will go to hell and the citizens will go to hell.

―Śrīla Bhaktivedānta Svāmī Prabhupāda
https://vanisource.org/wiki/Philosophy_Discussion_on_Hegel

Śrīla Lokanātha Gosvāmī had vowed that he would never accept disciples, because after awarding dīkṣā, if a disciple commits any sins the guru incurs one-sixth of the portion of those sins, just as the king has to incur one-sixth of the portion of the sins committed by his subjects. Therefore in Kali-yuga, kings cannot remain ‘dhārmika’ [religious or in other words, sinless]. This is mentioned in the Manu-smṛti.

―Śrīla Bhakti Vijñāna Bhāratī Gosvāmī Mahārāja
https://www.visuddhacaitanyavani.com/single-post/2018/08/04/Srila-Lokanatha-Gosvami

Because of sinful activities, at night we have bad dreams, which are very troublesome. Indeed, Mahārāja Yudhiṣṭhira was obliged to see hell because of a slight deviation from devotional service to the Lord. Therefore, duḥsvapna — bad dreams — occur because of sinful activities. A devotee sometimes accepts a sinful person as his disciple, and to counteract the sinful reactions he accepts from the disciple, he has to see a bad dream. Nonetheless, the spiritual master is so kind that in spite of having bad dreams due to the sinful disciple, he accepts this troublesome business for the deliverance of the victims of Kali-yuga. After initiation, therefore, a disciple should be extremely careful not to commit again any sinful act that might cause difficulties for himself and the spiritual master. Before the Deity, before the fire, before the spiritual master and before the Vaiṣṇavas, the honest disciple promises to refrain from all sinful activity. Therefore he must not again commit sinful acts and thus create a troublesome situation.

―Śrīla Bhaktivedānta Svāmī Prabhupāda
http://www.vedabase.com/en/sb/8/4/15

As Kṛṣṇa takes away all the sinful reactions of a person immediately upon his surrender unto Him, similarly the external manifestation of Kṛṣṇa, the representative of Kṛṣṇa who acts as the mercy of the Supreme Personality of Godhead, takes all the resultant actions of the sinful life of the disciple immediately after the disciple’s initiation. Thus if the disciple follows the principles instructed by the spiritual master, he remains purified and is not contaminated by the material infection.
Śrī Caitanya Mahāprabhu therefore stated that the spiritual master who plays the part of Kṛṣṇa’s representative has to consume all the sinful reactions of his disciple. Sometimes a spiritual master takes the risk of being overwhelmed by the sinful reactions of the disciples and undergoes a sort of tribulation due to their acceptance. Śrī Caitanya Mahāprabhu therefore advised that one not accept many disciples.

―Śrīla Bhaktivedānta Svāmī Prabhupāda
http://www.vedabase.com/en/sb/4/21/31

Sometimes the spiritual master, after accepting a disciple, must take charge of that disciple’s past sinful activities and, being overloaded, must sometimes suffer—if not fully, then partially—for the sinful acts of the disciple. Every disciple, therefore, must be very careful not to commit sinful activities after initiation. The poor spiritual master is kind and merciful enough to accept a disciple and partially suffer for that disciple’s sinful activities, but Kṛṣṇa, being merciful to His servant, neutralizes the reactions of sinful deeds for the servant who engages in preaching His glories.

―Śrīla Bhaktivedānta Svāmī Prabhupāda
http://www.vedabase.com/en/sb/9/9/5

avaiṣṇava-saṅga-tyāga, bahu-śiṣya nā kariba
bahu-grantha-kalābhyāsa-vyākhyāna varjiba

“The twelfth item is to give up the company of nondevotees. (13) One should not accept an unlimited number of disciples. (14) One should not partially study many scriptures just to be able to give references and expand explanations.

Accepting an unlimited number of devotees or disciples is very risky for one who is not a preacher. According to Śrīla Jīva Gosvāmī, a preacher has to accept many disciples to expand the cult of Śrī Caitanya Mahāprabhu. This is risky because when a spiritual master accepts a disciple, he naturally accepts the disciple’s sinful activities and their reactions. Unless he is very powerful, he cannot assimilate all the sinful reactions of his disciples and has to suffer the consequences. Therefore one is generally forbidden to accept many disciples.

―Śrīla Bhaktivedānta Svāmī Prabhupāda
http://www.vedabase.com/en/cc/madhya/22/118

Bahu-śiṣya-karaṇa-tyāgaḥ
Renouncing the desire to recruit many disciples

To make many disciples in order to accumulate wealth and increase one’s pride and prestige is one of the principal obstacles on the path of bhakti. In his commentary on Bhakti-rasāmṛtasindhu (1.2.113), Śrīla Jīva Gosvāmī has written that one should not accept many unqualified persons as disciples, even for the purpose of expanding the sampradāya: sva sva sampradāya vṛddyartham anadhikāriṇo ’pi na saṅgṛhṇīyāt. To make many disciples, one will have to accept many unqualified persons whose hearts are devoid of śraddhā. To make disciples of faithless persons is an offence, which presents obstacles in the practice of one’s bhajana, and ultimately one will have to fall down into hell.

Śrī Bhakti-rasāmṛta-sindhu-bindu, 3rd Edition (Śrīla Viśvanātha Cakravartī Ṭhākura)
Translation and commentary by Śrīla Bhaktivedānta Nārāyaṇa Mahārāja