CC Madhya 10.12

bhavad-vidhā bhāgavatās
tīrthī-bhūtāḥ svayaṁ vibho
tīrthī-kurvanti tīrthāni
svāntaḥ-sthena gadā-bhṛtā
Synonyms: 
bhavat — your good self; vidhāḥ — like; bhāgavatāḥ — devotees; tīrthī — as holy places of pilgrimage; bhūtāḥ — existing; svayam — themselves; vibho — O almighty one; tīrthī-kurvanti — make into holy places of pilgrimage; tīrthāni — the holy places; sva-antaḥ-sthena — being situated in their hearts; gadā-bhṛtā — by the Personality of Godhead.
Translation: 
“ ‘Saints of your caliber are themselves places of pilgrimage. Because of their purity, they are constant companions of the Lord, and therefore they can purify even the places of pilgrimage.’
Purport: 

This verse, spoken by Mahārāja Yudhiṣṭhira to Vidura in Śrīmad-Bhāgavatam (1.13.10), is also quoted in the Ādi-līlā (1.63).