leviticus 18:6 None of you shall approach to any that is near of kin to him, to uncover their nakedness: I am the LORD. - Free Bible Online

      6. None of you shall approach to any that is near of kin to him--Very great laxity prevailed amongst the Egyptians in their sentiments and practice about the conjugal relation, as they not only openly sanctioned marriages between brothers and sisters, but even between parents and children. Such incestuous alliances Moses wisely prohibited, and his laws form the basis upon which the marriage regulations of this and other Christian nations are chiefly founded. This verse contains a general summary of all the particular prohibitions; and the forbidden intercourse is pointed out by the phrase, "to approach to." In the specified prohibitions that follow, all of which are included in this general summary, the prohibited familiarity is indicated by the phrases, to "uncover the nakedness" [Le 18:12-17], to "take" [Le 18:17, 18], and to "lie with" [Le 18:22, 23]. The phrase in this sixth verse, therefore, has the same identical meaning with each of the other three, and the marriages in reference to which it is used are those of consanguinity or too close affinity, amounting to incestuous connections.

JFB.