Yevamos 20b-21b
The bizarre case of quasi-levirate marriage \u2022 Chalitzah (severance of the levirate bond) is not considered an imperative in relation to levirate marriage \u2022 How do we know that second degree relatives, Shniyos, are prohibited from a biblically derived tradition? \u2022 How does the Maggid Mishnah prove the paradoxical nature of forbidden incestuous relationships? \u2022 In what manner is the violation of deceptive weights and measures more severe than illicit relationships? \u2022 Is one's father-in-law's wife always prohibited? \u2022 May stepchildren marry? \u2022 May a king's wife remarry?