Mand. lbab functions as the abs. and constr. of liba

See also s.v. lb. It may well be that in some sub-dialects or idiolects lb and lbb are distinguished, i.e. between a physical organ and "mind", but more study is needed. In any case, the figurative usages far overwhelm the physical in our sources.
Note that in Syriac this form is so far attested only in magical texts, i..e, certainly simply copied from a JBA formula.