The book's rule is to keep ṭūl broadly equal across the four kinds of madd lāzim. It notes minor comparative descriptions, but the controlling principle is equivalence.
Lāzim involves an original sukūn or shaddah, whereas temporary madd arises from a pause. Do not infer the measure of one category from the other.
Opening interactive controls...
Length across the four kinds of lāzim
Madd Lengths and Permissible Combinations — Ṭūl, Tawassuṭ, Qaṣr and Consistency
The book's rule is to keep ṭūl broadly equal across the four kinds of madd lāzim. It notes minor comparative descriptions, but the controlling principle is equivalence.
Lāzim involves an original sukūn or shaddah, whereas temporary madd arises from a pause. Do not infer the measure of one category from the other.