Source: How shall I serve you?
Once in a room with many disciples, Śrīla Bhaktisiddhānta Sarasvatī was speaking and 
Abhay listening when an old man beside Abhay motioned to him. As Abhay leaned over to hear what the man wanted, Śrīla Bhaktisiddhānta suddenly spoke out in annoyance at the two apparently inattentive students. “Bābū,” he first addressed the old man beside Abhay, “do you think you have purchased me with your 150-rupees-per-month donation?” And then, turning to Abhay: “Why don’t you come up here and speak instead of me?” Abhay was outwardly mortified, yet he treasured the rebuke.