Traditionally, 18:22 has been read as a clear condemnation of male homosexual acts. The debate has then been over the
hermeneutical question of whether and how, this text applies to the modern Christian or Jewish situation (see
The Bible and homosexuality for that debate).
However, there are also debates as to the meaning of the verse itself:
Many authors (including Greenberg 1988:191, Wenham 1979:259, Kahn 1984:49) state that v.22 condemns homosexuality or homosexual relations without explaining what these words mean.
Alternatively, some authors state that v.22 condemns only males penetrating males (anal intercourse). These authors include Babylonian Talmud Sanhedrin 54a and b; Josephus, Against Apion 2.199; and Philo, Abraham 135. Some modern authors stating this view include Alter 2004:623, 632; Boyarin 1995:339, 343; Brooten 1996:61; Cohen 1990:6; Daube 1986:447; Milgrom 2000:1568; Olyan 1994:185; Thurston 1990:16; and Walsh 2001:208.
The papers by Olyan and Walsh show how they conclude that v.22 refers only to men penetrating men. In brief, the verse only prohibits a male having sex (lying) with another male when the sex is the lyings of a woman (mikəḇē ʼiā

. The phrase the lyings of a woman is the opposite of the lying of a male, which in the Old Testament (eg
Book of Numbers 31:1718, 35, and
Judges 21:1112) means male vaginal penetration. The opposite of this is female vaginal receptivity the meaning of the lyings of a woman. The male equivalent of vaginal receptivity is anal receptivity. Therefore v.22 prohibits a male from having anal sex (lying) with another male.
On the other hand, some authors state that v.22 condemns all sex acts between males. These authors include Gagnon 2001:143; and Wold 1998:95.
Some note that v.22 uses the Hebrew phrase, לֹא תִשְׁכַּב "lō ṯikaḇ", which could be referring to any form of laying down to rest. In the surrounding sexual-condemnation passages v.20 and v.23, the phrase לֹא־תִתֵּן שְׁכָבְתְּךָ "lō-ṯittēn əḵoḇtəḵā" is used, which is quite specifically about sex. Some argue that the lack of parallelism between these statements is an indicator that passage v.22 is deliberately phrased to not talk explicitly about sex.
Others note v.22 concerns מִשְׁכְּבֵי אִשָּׁה "mikəḇē ʼiā", literally "the bed(chambers) of (a) woman." They argue that, while this can be an
indirect reference to sexuality, it is never used as directly as the English translation seems to indicate. They note that מִשְׁכַּב "mikaḇ" can only used euphemistically to refer to sex, e.g. Numbers 31:18, lit. "women who have known man in the bed of man." They deny that this is a euphemistic use. Also, תִּשְׁכַּב "tikaḇ" could refer to any form of rest (Gen 19:4, 28:11-13, 47:30, Exd 22:27, Lev 14:47, 26:6, Num 23:24, et al).
Conservative theologians have responded that there are many instances of תִּשְׁכַּב "tikaḇ" referring explicitly to sex (Gen 19:34, 26:10, 30:15-16, 34:2, 35:22, 39:7, Exd 22:16, 22:19, et al). Moreover, they argue, the entire context of Leviticus 18 seems to deal with sexual things, and that this rendition of "lie with" is likewise sexual
[2]. See, for example, Wold 1998:107.
Liberal theologians have responded to this by noting that v.21 immediately precedes v.22, but is not sexual, hence the context is broken in at least one, and possibly two, passages, before getting reasserted by the parallelism of v.20 and v.23. (But note that Cohen (1990:13) states that seed (zera) in v.21 means sperm, not offspring or children, and offering sperm to Molech is a sexual act).
Some also dispute the type of condemnation present in v.22. The verse identifies that the form of condemnation is תֹּועֵבָה "tōʻēḇā". The earlier crimes referenced in Leviticus 18 (the nakedness crimes), are specifically identified as זִמָּה zimmā. תֹּועֵבָה "Tōʻēḇā" is a word strictly concerning the sin of idolatry (Gen 43:32, 46:34, Exd 8:26, Deut 7:25, 13:12-14, et al). זִמָּה Zimmā seems a more appropriate word to talk about sexual crimes (Lev 18:17, 19:29, 20:14, Judges 20:5-6, Jer 13:27, Eze 16:26-27, et al).
http://en.wikipedia.org/wiki/Leviticus_18