Why does مِنْ رَبِّهِ وَالْمُؤْمِنُونَ receive ṣilah?

Rules of Hāʾ al-Ḍamīr: Vowels, Ṣilah and Exceptions

• Every word is followed by wāw
• Both immediate neighbors of hāʾ are vowelled
• There is an earlier nūn
• Every kasrah hāʾ is lengthened