Genesis 29:16-20 (KJV)
16 And Laban had two daughters: the name of the elder was Leah, and the name of the younger was Rachel. 17 Leah was tender eyed; but Rachel was beautiful and well favoured. 18 And Jacob loved Rachel; and said, I will serve thee seven years for Rachel thy younger daughter. 19 And Laban said, It is better that I give her to thee, than that I should give her to another man: abide with me. 20 And Jacob served seven years for Rachel; and they seemed unto him but a few days, for the love he had to her.
Genesis 29:25-26 (KJV)
25 And it came to pass, that in the morning, behold, it was Leah: and he said to Laban, What is this thou hast done unto me? did not I serve with thee for Rachel? wherefore then hast thou beguiled me? 26 And Laban said, It must not be so done in our country, to give the younger before the firstborn.