"Sādhu is titikṣava, tolerates all kinds of miserable condition. He is sādhu. Because this is a place of miserable condition. A sādhu learns how to tolerate. Sādhu is never disturbed. Yasmin sthite guruṇāpi duḥkhena na vicālyate (BG 6.21). A sādhu who has got the shelter of Kṛṣṇa, if he is placed in the severest type of dangerous condition, he is never disturbed. Just like Prahlāda Mahārāja: his father was putting him in so many dangerous condition, even he was supplying with poison.
He knew that 'My father has given me poison to drink. All right, let me drink. If Kṛṣṇa likes, He will save me. I am now put into such dangerous position, I have to drink. Father is giving poison. Who can check?' And such a big, powerful Hiraṇyakaśipu. The mother cried, requested... He forced the mother, Prahlāda's mother, 'Give your son this poison.' So she begged so much, but he was a rascal demon. 'No, you must give.'
So the mother knew, the son knew that the rascal father is giving this poison. What can he do, a small child? 'All right, let me drink.' Guruṇāpi duḥkhena na vicālyate (BG 6.22). He is not agitating. 'All right. If Kṛṣṇa likes, I will like.' This is the position of sādhu. He is not disturbed. Titikṣavaḥ. In all circumstances he is tolerant. That is sādhu. Sādhu does not become disturbed. Titikṣavaḥ. At the same time, kāruṇikāḥ. He is himself disturbed, but he is merciful to others.
Just like Jesus Christ. He is being crucified, and still he is merciful: 'God, these people do not know what they are doing. Please excuse them.' This is sādhu. He is personally being disturbed by the demons, but still, he is merciful to the general people. They are suffering for want of Kṛṣṇa consciousness. So even up to the point of death, he is trying to preach Kṛṣṇa consciousness. 'Let the people be benefited. Eh, what is this material body? Even if I am killed, I am not killed. This body is killed, that's all.' This is sādhu. Titikṣavaḥ kāruṇikāḥ. In one side he is tolerant, and other side, merciful.
The material world, when one man is disturbed, he cannot do any beneficial work to any others. He is disturbed. 'No, I am very much disturbed. Don't talk with me.' No. But sādhu still goes on benefiting the people in general. Titikṣavaḥ kāruṇikāḥ (SB 3.25.21). And what kind of benefit? The so-called rascals' humanitarian work? No. Suhṛdaṁ sarva-bhūtānām (BG 5.29). He is beneficial to all kinds of living entities."
(Srila Prabhupada Lecture, London, July 18, 1973)