CC Antya 15.50

kṛṣṇe dekhi’ ei saba karena namaskāra
kṛṣṇa-gamana puche tāre kariyā nirdhāra
Word for word: 
kṛṣṇe dekhi’ — seeing Kṛṣṇa; ei — these; saba — all; karena namaskāra — offer respectful obeisances; kṛṣṇa-gamana — the passing of Kṛṣṇa; puche — inquire; tāre — from them; kariyā nirdhāra — making certain.
Translation: 
The gopīs thought that because all the trees must have seen Kṛṣṇa pass by they were offering respectful obeisances to Him. To be certain, the gopīs inquired from the trees.