Bhagavad Gita 2.10

“Tam uvāca hṛṣīkeśaḥ

prahasann iva bhārata

senayor ubhayor madhye

viṣīdantam idaṁ vacaḥ”

Tam—unto him; uvāca—said; hṛṣīkeśaḥ—the master of the senses, Kṛṣṇa; prahasan—smiling; iva—like that; bhārata—O Dhṛtarāṣṭra, descendant of Bharata; senayoḥ—of the armies; ubhayoḥ—of both parties; madhye—between; viṣīdantam—unto the lamenting one; idam—the following; vacaḥ—words.

Translation: “O descendant of Bharata, at that time Kṛṣṇa, smiling, in the midst of both the armies, spoke the following words to the grief-stricken Arjuna.”

The answer comes in Bhagavad Gita, the first text book of counseling. When grief ridden Arjuna approaches Krishna, he starts his counseling in a happy and smiling mood.

Arjuna was grief-filled, sad and rebellious. Yet Krishna smiled. The word in the Gita is prahasann, which means to smile before laughing (beginning to laugh).

It was not a weak or full smile or a sarcastic grimace, but a very positive smile.

Half of grief/apprehension is alleviated if a patient sees his doctor smiling or the relatives see a smile on the face of a doctor coming out of operation theatre.

It also gives confidence to the patient (Arjuna) that his doctor (Krishna) has understood his problem fully and has a solution to his problem.

Buddha is also shown smiling and Goddess Kushmanda is also shown with a smiling face.