SB 10.39.11-12

gopān samādiśat so ’pi
 gṛhyatāṁ sarva-go-rasaḥ
upāyanāni gṛhṇīdhvaṁ
 yujyantāṁ śakaṭāni ca
yāsyāmaḥ śvo madhu-purīṁ
 dāsyāmo nṛpate rasān
drakṣyāmaḥ su-mahat parva
 yānti jānapadāḥ kila
evam āghoṣayat kṣatrā
 nanda-gopaḥ sva-gokule
Synonyms: 
gopān — the cowherd men; samādiśāt — ordered; saḥ — he (Nanda Mahārāja); api — also; gṛhyatām — have collected; sarva — all; go-rasaḥ — the milk products; upāyanāni — excellent gifts; gṛhṇīdhvam — take; yujyantām — yoke; śakaṭāni — the wagons; ca — and; yāsyāmaḥ — we shall go; śvaḥ — tomorrow; madhu-purīm — to Mathurā; dāsyāmaḥ — we shall give; nṛpateḥ — to the King; rasān — our milk products; drakṣyāmaḥ — we shall see; su-mahat — a very great; parva — festival; yānti — are going; jānapadāḥ — the residents of all the outlying districts; kila — indeed; evam — thus; āghoṣayat — he had announced; kṣatrā — by the village constable; nanda-gopaḥ — Nanda Mahārāja; sva-gokule — to the people of his Gokula.
Translation: 
Nanda Mahārāja then issued orders to the cowherd men by having the village constable make the following announcement throughout Nanda’s domain of Vraja: “Go collect all the available milk products. Bring valuable gifts and yoke your wagons. Tomorrow we shall go to Mathurā, present our milk products to the King and see a very great festival. The residents of all the outlying districts are also going.”
Purport: 

Nanda wanted to bring ghee and other milk products as taxes for the King.