Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 4
सख्यं मैत्रीं सौहृदं च सारथ्यादिषु संस्मरन् ।नृपमग्रजमित्याह बाष्पगद्गदया गिरा ॥ ४ ॥
sakhyaṁ maitrīṁ sauhṛdaṁ casārathyādiṣu saṁsmarannṛpam agrajam ity āhabāṣpa-gadgadayā girā
Remembering Lord Kṛṣṇa and His well wishes, benefactions, intimate familial relations and His chariot driving, Arjuna, overwhelmed and breathing very heavily, began to speak.
The supreme living being is perfect in all relations with His pure devotee. Śrī Arjuna is one of the typical pure devotees of the Lord reciprocating in the fraternal relationship, and the Lord’s dealings with Arjuna are displays of friendship of the highest perfect order. He was not only a well-wisher of Arjuna but actually a benefactor, and to make it still more perfect the Lord tied him into a family relationship by arranging Subhadrā’s marriage with him. And above all, the Lord agreed to become a chariot driver of Arjuna in order to protect His friend from warfare risks, and the Lord became actually happy when He established the Pāṇḍavas to rule over the world. Arjuna remembered all these one after another, and thus he became overwhelmed with such thoughts.