Matsya Purana 264.36

264.36

lakṣaṇoddharaṇaṃ vakṣye liṅgasya susamāhitaḥ.
tridhā vibhajya pūjyāyāṃ lakṣaṇaṃ syād vibhājakam .. 264.35

The image should be divided into three parts and afterwards three lines at a distance of eight Yavas from one another should be drawn which should be broad, thin and crooked They should not be broken (i e., should be continuous)—35 36