Śrī Śukadeva Gosvāmī said: When the great devotee Uddhava was asked by Vidura to speak on the messages of the dearest [Lord Kṛṣṇa], Uddhava was unable to answer immediately due to excessive anxiety at the remembrance of the Lord.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
श्रीशुक उवाच । इति भागवतः पृष्टः क्षत्त्रा वार्तां प्रियाश्रयाम् । प्रतिवक्तुं न चोत्सेह औत्कण्ठ्यात्स्मारितेश्वरः
śrīśuka uvāca | iti bhāgavataḥ pṛṣṭaḥ kṣattrā vārtāṃ priyāśrayām | prativaktuṃ na cotseha autkaṇṭhyātsmāriteśvaraḥ
SB 3.2.1