One verse

Srimad Bhagavatam 11.17.39

11.17.39

गृहार्थी सद‍ृशीं भार्यामुद्वहेदजुगुप्सिताम् । यवीयसीं तु वयसा यां सवर्णामनुक्रमात् ॥ ३९ ॥

gṛhārthī sadṛśīṁ bhāryām udvahed ajugupsitām yavīyasīṁ tu vayasā yāṁ sa-varṇām anu kramāt

gṛha
household
arthī
one who desires
sadṛśīm
possessing similar characteristics
bhāryām
a wife
udvahet
one should marry
ajugupsitām
beyond reproach
yavīyasīm
younger
tu
indeed
vayasā
by age
yām
another wife
sa-varṇām
the first wife who is of the same caste
anu
after
kramāt
in succession

One who desires to establish family life should marry a wife of his own caste, who is beyond reproach and younger in age. If one desires to accept many wives he must marry them after the first marriage, and each wife should be of a successively lower caste.