Мидраш к Шмуэль Б 13:38

Rabbi José said: Isaac observed mourning during three years || for his mother. After three years he married Rebecca, and forgot the mourning for his mother. Hence thou mayest learn that until a man marries a wife his love centres in his parents. When he marries a wife his love is bestowed upon his wife, as it is said, "Therefore shall a man leave his father and his mother, and he shall cleave unto his wife" (Gen. 2:24). Does a man then leave his father and mother with reference to the precept, "Honour"? But the love of his soul cleaves unto his wife, as it is said, "And his soul clave (unto Dinah)" (Gen. 34:3); and it says, "And he shall cleave unto his wife" (Gen. 2:24).